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# Release History

This page provides a high-level summary of changes to SQLite. For more detail, see the Fossil checkin logs at http://www.sqlite.org/src/timeline and http://www.sqlite.org/src/timeline?t=release. See the chronology a succinct listing of releases.

### 2016-04-18 (3.12.2)

- Fix a backwards compatibility problem in version 3.12.0 and 3.12.1: Columns declared as `"INTEGER" PRIMARY KEY` (with quotes around the datatype keyword) where not being recognized as an INTEGER PRIMARY KEY, which resulted in an incompatible database file. Ticket 7d7525cb01b68
- Fix a bug (present since version 3.9.0) that can cause the DELETE operation to miss rows if PRAGMA reverse_unordered_selects is turned on. Ticket a306e56ff68b8fa5
- Fix a bug in the code generator that can causes incorrect results if two or more virtual tables are joined and the virtual table used in outer loop of the join has an IN operator constraint.
- Correctly interpret negative "PRAGMA cache_size" values when determining the cache size used for sorting large amounts of data.

  Hashes:

- SQLITE_SOURCE_ID: "2016-04-18 17:30:31 92dc59fd5ad66f646666042eb04195e3a61a9e8e"
- SHA1 for sqlite3.c: de5a5898ebd3a3477d4652db143746d008b24c83

### 2016-04-08 (3.12.1)

- Fix a boundary condition error introduced by version 3.12.0 that can result in a crash during heavy SAVEPOINT usage. Ticket 7f7f8026eda38.
- Fix views so that they inherit column datatypes from the table that they are defined against, when possible.
- Fix the query planner so that IS and IS NULL operators are able to drive an index on a LEFT OUTER JOIN.

  Hashes:

- SQLITE_SOURCE_ID: "2016-04-08 15:09:49 fe7d3b75fe1bde41511b323925af8ae1b910bc4d"
- SHA1 for sqlite3.c: ebb18593350779850e3e1a930eb84a70fca8c1d1

### 2016-04-01 (3.9.3)

- Backport a simple query planner optimization that allows the IS operator to drive an index on a LEFT OUTER JOIN. No other changes from the version 3.9.2 baseline.

### 2016-03-29 (3.12.0)

Potentially Disruptive Change:

- The SQLITE_DEFAULT_PAGE_SIZE is increased from 1024 to 4096. The SQLITE_DEFAULT_CACHE_SIZE is changed from 2000 to -2000 so the same amount of cache memory is used by default. See the application note on the version 3.12.0 page size change for further information.

  Performance enhancements:

- Enhancements to the Lemon parser generator so that it creates a smaller and faster SQL parser.
- Only create master journal files if two or more attached databases are all modified, do not have PRAGMA synchronous set to OFF, and do not have the journal_mode set to OFF, MEMORY, or WAL.
- Only create statement journal files when their size exceeds a threshold. Otherwise the journal is held in memory and no I/O occurs. The threshold can be configured at compile-time using SQLITE_STMTJRNL_SPILL or at start-time using sqlite3_config(SQLITE_CONFIG_STMTJRNL_SPILL).
- The query planner is able to optimize IN operators on virtual tables even if the xBestIndex method does not set the sqlite3_index_constraint_usage.omit flag of the virtual table column to the left of the IN operator.
- The query planner now does a better job of optimizing virtual table accesses in a 3-way or higher join where constraints on the virtual table are split across two or more other tables of the join.
- More efficient handling of application-defined SQL functions, especially in cases where the application defines hundreds or thousands of custom functions.
- The query planner considers the LIMIT clause when estimating the cost of ORDER BY.
- The configure script (on unix) automatically detects pread() and pwrite() and sets compile-time options to use those OS interfaces if they are available.
- Reduce the amount of memory needed to hold the schema.
- Other miscellaneous micro-optimizations for improved performance and reduced memory usage.

  New Features:

- Added the SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER option to sqlite3_db_config() which allows the two-argument version of the fts3_tokenizer() SQL function to be enabled or disabled at run-time.
- Added the sqlite3rbu_bp_progress() interface to the RBU extension.
- The PRAGMA defer_foreign_keys=ON statement now also disables RESTRICT actions on foreign key.
- Added the sqlite3_system_errno() interface.
- Added the SQLITE_DEFAULT_SYNCHRONOUS and SQLITE_DEFAULT_WAL_SYNCHRONOUS compile-time options. The SQLITE_DEFAULT_SYNCHRONOUS compile-time option replaces the SQLITE_EXTRA_DURABLE option, which is no longer supported.
- Enhanced the ".stats" command in the command-line shell to show more information about I/O performance obtained from /proc, when available.

  Bug fixes:

- Make sure the sqlite3_set_auxdata() values from multiple triggers within a single statement do not interfere with one another. Ticket dc9b1c91.
- Fix the code generator for expressions of the form "x IN (SELECT...)" where the SELECT statement on the RHS is a correlated subquery. Ticket 5e3c886796e5512e.
- Fix a harmless TSAN warning associated with the sqlite3_db_readonly() interface.

  Hashes:

- SQLITE_SOURCE_ID: "2016-03-29 10:14:15 e9bb4cf40f4971974a74468ef922bdee481c988b"
- SHA1 for sqlite3.c: cba2be96d27cb51978cd4a200397a4ad178986eb

### 2016-03-03 (3.11.1)

- Improvements to the Makefiles and build scripts used by VisualStudio.
- Fix an FTS5 issue in which the 'optimize' command could cause index corruption.
- Fix a buffer overread that might occur if FTS5 is used to query a corrupt database file.
- Increase the maximum "scope" value for the spellfix1 extension from 6 to 30.
- SQLITE_SOURCE_ID: "2016-03-03 16:17:53 f047920ce16971e573bc6ec9a48b118c9de2b3a7"
- SHA1 for sqlite3.c: 3da832fd2af36eaedb05d61a8f4c2bb9f3d54265

### 2016-02-15 (3.11.0)

General improvements:

- Enhanced WAL mode so that it works efficiently with transactions that are larger than the cache_size.
- Added the FTS5 detail option.
- Added the "EXTRA" option to PRAGMA synchronous that does a sync of the containing directory when a rollback journal is unlinked in DELETE mode, for better durability. The SQLITE_EXTRA_DURABLE compile-time option enables PRAGMA synchronous=EXTRA by default.
- Enhanced the query planner so that it is able to use a covering index as part of the OR optimization.
- Avoid recomputing NOT NULL and CHECK constraints on unchanged columns in UPDATE statement.
- Many micro-optimizations, resulting in a library that is faster than the previous release.

  Enhancements to the command-line shell:

- By default, the shell is now in "auto-explain" mode. The output of EXPLAIN commands is automatically formatted.
- Added the ".vfslist" dot-command.
- The SQLITE_ENABLE_EXPLAIN_COMMENTS compile-time option is now turned on by default in the standard builds.

  Enhancements to the TCL Interface:

- If a database connection is opened with the "-uri 1" option, then URI filenames are honored by the "backup" and "restore" commands.
- Added the "-sourceid" option to the "sqlite3" command.

  Makefile improvements:

- Improved pthreads detection in configure scripts.
- Add the ability to do MSVC Windows builds from the amalgamation tarball.

  Bug fixes

- Fix an issue with incorrect sharing of VDBE temporary registers between co-routines that could cause incorrect query results in obscure cases. Ticket d06a25c84454a.
- Fix a problem in the sqlite3_result_subtype() interface that could cause problems for the json1 extension under obscure circumstances. Fix for ticket f45ac567eaa9f9.
- Escape control characters in JSON strings. Fix for ticket ad2559db380abf8.
- Reenable the xCurrentTime and xGetLastError methods in the built-in unix VFSes as long as SQLITE_OMIT_DEPRECATED is not defined.

  Backwards Compatibility:

- Because of continuing security concerns, the two-argument version of of the seldom-used and little-known fts3_tokenizer() function is disabled unless SQLite is compiled with the SQLITE_ENABLE_FTS3_TOKENIZER.

  Hashes:

- SQLITE_SOURCE_ID: "2016-02-15 17:29:24 3d862f207e3adc00f78066799ac5a8c282430a5f"
- SHA1 for sqlite3.c: df01436c5fcfe72d1a95bc172158219796e1a90b

### 2016-01-20 (3.10.2)

Critical bug fix:

- Version 3.10.0 introduced a case-folding bug in the LIKE operator which is fixed by this patch release. Ticket 80369eddd5c94.

  Other miscellaneous bug fixes:

- Fix a use-after-free that can occur when SQLite is compiled with -DSQLITE_HAS_CODEC.
- Fix the build so that it works with -DSQLITE_OMIT_WAL.
- Fix the configure script for the amalgamation so that the --readline option works again on Raspberry PIs.

  Hashes:

- SQLITE_SOURCE_ID: "2016-01-20 15:27:19 17efb4209f97fb4971656086b138599a91a75ff9"
- SHA1 for sqlite3.c: f7088b19d97cd7a1c805ee95c696abd54f01de4f

### 2016-01-14 (3.10.1)

New feature:

- Add the SQLITE_FCNTL_JOURNAL_POINTER file control.

  Bug fix:

- Fix a 16-month-old bug in the query planner that could generate incorrect results when a scalar subquery attempts to use the block sorting optimization. Ticket cb3aa0641d9a4.

  Hashes:

- SQLITE_SOURCE_ID: "2016-01-13 21:41:56 254419c36766225ca542ae873ed38255e3fb8588"
- SHA1 for sqlite3.c: 1398ba8e4043550a533cdd0834bfdad1c9eab0f4

### 2016-01-06 (3.10.0)

General improvements:

- Added support for LIKE, GLOB, and REGEXP operators on virtual tables.
- Added the colUsed field to sqlite3_index_info for use by the sqlite3_module.xBestIndex method.
- Enhance the PRAGMA cache_spill statement to accept a 32-bit integer parameter which is the threshold below which cache spilling is prohibited.
- On unix, if a symlink to a database file is opened, then the corresponding journal files are based on the actual filename, not the symlink name.
- Added the "--transaction" option to sqldiff.
- Added the sqlite3_db_cacheflush() interface.
- Added the sqlite3_strlike() interface.
- When using memory-mapped I/O map the database file read-only so that stray pointers and/or array overruns in the application cannot accidently modify the database file.
- Added the experimental sqlite3_snapshot_get(), sqlite3_snapshot_open(), and sqlite3_snapshot_free() interfaces. These are subject to change or removal in a subsequent release.
- Enhance the 'utc' modifier in the date and time functions so that it is a no-op if the date/time is known to already be in UTC. (This is not a compatibility break since the behavior has long been documented as "undefined" in that case.)
- Added the json_group_array() and json_group_object() SQL functions in the json extension.
- Added the SQLITE_LIKE_DOESNT_MATCH_BLOBS compile-time option.
- Many small performance optimizations.

  Portability enhancements:

- Work around a sign-exension bug in the optimizer of the HP C compiler on HP/UX. (details)

  Enhancements to the command-line shell:

- Added the ".changes ON|OFF" and ".vfsinfo" dot-commands.
- Translate between MBCS and UTF8 when running in cmd.exe on Windows.

  Enhancements to makefiles:

- Added the --enable-editline and --enable-static-shell options to the various autoconf-generated configure scripts.
- Omit all use of "awk" in the makefiles, to make building easier for MSVC users.

  Important fixes:

- Fix inconsistent integer to floating-point comparison operations that could result in a corrupt index if the index is created on a table column that contains both large integers and floating point values of similar magnitude. Ticket 38a97a87a6.
- Fix an infinite-loop in the query planner that could occur on malformed common table expressions.
- Various bug fixes in the sqldiff tool.

  Hashes:

- SQLITE_SOURCE_ID: "2016-01-06 11:01:07 fd0a50f0797d154fefff724624f00548b5320566"
- SHA1 for sqlite3.c: b92ca988ebb6df02ac0c8f866dbf3256740408ac

### 2015-11-02 (3.9.2)

- Fix the schema parser so that it interprets certain (obscure and ill-formed) CREATE TABLE statements the same as legacy. Fix for ticket ac661962a2aeab3c331
- Fix a query planner problem that could result in an incorrect answer due to the use of automatic indexing in subqueries in the FROM clause of a correlated scalar subqueries. Fix for ticket 8a2adec1.
- SQLITE_SOURCE_ID: "2015-11-02 18:31:45 bda77dda9697c463c3d0704014d51627fceee328"
- SHA1 for sqlite3.c: 1c4013876f50bbaa3e6f0f98e0147c76287684c1

### 2015-10-16 (3.9.1)

- Fix the json1 extension so that it does not recognize ASCII form-feed as a whitespace character, in order to comply with RFC-7159. Fix for ticket 57eec374ae1d0a1d
- Add a few #ifdef and build script changes to address compilation issues that appeared after the 3.9.0 release.
- SQLITE_SOURCE_ID: ""2015-10-16 17:31:12 767c1727fec4ce11b83f25b3f1bfcfe68a2c8b02"
- SHA1 for sqlite3.c: 5e6d1873a32d82c2cf8581f143649940cac8ae49

### 2015-10-14 (3.9.0)

Policy Changes:

- The version numbering conventions for SQLite are revised to use the emerging standard of semantic versioning.

  New Features And Enhancements:

- Added the json1 extension module in the source tree, and in the amalgamation. Enable support using the SQLITE_ENABLE_JSON1 compile-time option.
- Added Full Text Search version 5 (FTS5) to the amalgamation, enabled using SQLITE_ENABLE_FTS5. FTS5 will be considered "experimental" (subject to incompatible changes) for at least one more release cycle.
- The CREATE VIEW statement now accepts an optional list of column names following the view name.
- Added support for indexes on expressions.
- Added support for table-valued functions in the FROM clause of a SELECT statement.
- Added support for eponymous virtual tables.
- A VIEW may now reference undefined tables and functions when initially created. Missing tables and functions are reported when the VIEW is used in a query.
- Added the sqlite3_value_subtype() and sqlite3_result_subtype() interfaced (used by the json1 extension).
- The query planner is now able to use partial indexes that contain AND-connected terms in the WHERE clause.
- The sqlite3_analyzer.exe utility is updated to report the depth of each btree and to show the average fanout for indexes and WITHOUT ROWID tables.
- Enhanced the dbstat virtual table so that it can be used as a table-valued function where the argument is the schema to be analyzed.

  Other changes:

- The sqlite3_memory_alarm() interface, which has been deprecated and undocumented for 8 years, is changed into a no-op.

  Important fixes:

- Fixed a critical bug in the SQLite Encryption Extension that could cause the database to become unreadable and unrecoverable if a VACUUM command changed the size of the encryption nonce.
- Added a memory barrier in the implementation of sqlite3_initialize() to help ensure that it is thread-safe.
- Fix the OR optimization so that it always ignores subplans that do not use an index.
- Do not apply the WHERE-clause pushdown optimization on terms that originate in the ON or USING clause of a LEFT JOIN. Fix for ticket c2a19d81652f40568c.
- SQLITE_SOURCE_ID: "2015-10-14 12:29:53 a721fc0d89495518fe5612e2e3bbc60befd2e90d"
- SHA1 for sqlite3.c: c03e47e152ddb9c342b84ffb39448bf4a2bd4288

### 2015-07-29 (3.8.11.1)

- Restore an undocumented side-effect of PRAGMA cache_size: force the database schema to be parsed if the database has not been previously accessed.
- Fix a long-standing problem in sqlite3_changes() for WITHOUT ROWID tables that was reported a few hours after the 3.8.11 release.
- SQLITE_SOURCE_ID: "2015-07-29 20:00:57 cf538e2783e468bbc25e7cb2a9ee64d3e0e80b2f"
- SHA1 for sqlite3.c: 3be71d99121fe5b17f057011025bcf84e7cc6c84

### 2015-07-27 (3.8.11)

- Added the experimental RBU extension. Note that this extension is experimental and subject to change in incompatible ways.
- Added the experimental FTS5 extension. Note that this extension is experimental and subject to change in incompatible ways.
- Added the sqlite3_value_dup() and sqlite3_value_free() interfaces.
- Enhance the spellfix1 extension to support ON CONFLICT clauses.
- The IS operator is now able to drive indexes.
- Enhance the query planner to permit automatic indexing on FROM-clause subqueries that are implemented by co-routine.
- Disallow the use of "rowid" in common table expressions.
- Added the PRAGMA cell_size_check command for better and earlier detection of database file corruption.
- Added the matchinfo 'b' flag to the matchinfo() function in FTS3.
- Improved fuzz-testing of database files, with fixes for problems found.
- Add the fuzzcheck test program and automatically run this program using both SQL and database test cases on "make test".
- Added the SQLITE_MUTEX_STATIC_VFS1 static mutex and use it in the Windows VFS.
- The sqlite3_profile() callback is invoked (by sqlite3_reset() or sqlite3_finalize()) for statements that did not run to completion.
- Enhance the page cache so that it can preallocate a block of memory to use for the initial set page cache lines. Set the default preallocation to 100 pages. Yields about a 5% performance increase on common workloads.
- Miscellaneous micro-optimizations result in 22.3% more work for the same number of CPU cycles relative to the previous release. SQLite now runs twice as fast as version 3.8.0 and three times as fast as version 3.3.9. (Measured using cachegrind on the speedtest1.c workload on Ubuntu 14.04 x64 with gcc 4.8.2 and -Os. Your performance may vary.)
- Added the sqlite3_result_zeroblob64() and sqlite3_bind_zeroblob64() interfaces.

  Important bug fixes:

- Fix CREATE TABLE AS so that columns of type TEXT never end up holding an INT value. Ticket f2ad7de056ab1dc9200
- Fix CREATE TABLE AS so that it does not leave NULL entries in the sqlite_master table if the SELECT statement on the right-hand side aborts with an error. Ticket 873cae2b6e25b
- Fix the skip-scan optimization so that it works correctly when the OR optimization is used on WITHOUT ROWID tables. Ticket 8fd39115d8f46
- Fix the sqlite3_memory_used() and sqlite3_memory_highwater() interfaces so that they actually do provide a 64-bit answer.

  Hashes:

- SQLITE_SOURCE_ID: "2015-07-27 13:49:41 b8e92227a469de677a66da62e4361f099c0b79d0"
- SHA1 for sqlite3.c: 719f6891abcd9c459b5460b191d731cd12a3643e

### 2015-05-20 (3.8.10.2)

- Fix an index corruption issue introduced by version 3.8.7. An index with a TEXT key can be corrupted by an INSERT into the corresponding table if the table has two nested triggers that convert the key value to INTEGER and back to TEXT again. Ticket 34cd55d68e0
- SQLITE_SOURCE_ID: "2015-05-20 18:17:19 2ef4f3a5b1d1d0c4338f8243d40a2452cc1f7fe4"
- SHA1 for sqlite3.c: 638abb77965332c956dbbd2c8e4248e84da4eb63

### 2015-05-09 (3.8.10.1)

- Make sqlite3_compileoption_used() responsive to the SQLITE_ENABLE_DBSTAT_VTAB compile-time option.
- Fix a harmless warning in the command-line shell on some versions of MSVC.
- Fix minor issues with the dbstat virtual table.
- SQLITE_SOURCE_ID: "2015-05-09 12:14:55 05b4b1f2a937c06c90db70c09890038f6c98ec40"
- SHA1 for sqlite3.c: 85e4e1c08c7df28ef61bb9759a0d466e0eefbaa2

### 2015-05-07 (3.8.10)

- Added the sqldiff.exe utility program for computing the differences between two SQLite database files.
- Added the matchinfo y flag to the matchinfo() function of FTS3.
- Performance improvements for ORDER BY, VACUUM, CREATE INDEX, PRAGMA integrity_check, and PRAGMA quick_check.
- Fix many obscure problems discovered while SQL fuzzing.
- Identify all methods for important objects in the interface documentation. (example)
- Made the American Fuzzy Lop fuzzer a standard part of SQLite's testing strategy.
- Add the ".binary" and ".limits" commands to the command-line shell.
- Make the dbstat virtual table part of standard builds when compiled with the SQLITE_ENABLE_DBSTAT_VTAB option.
- SQLITE_SOURCE_ID: "2015-05-07 11:53:08 cf975957b9ae671f34bb65f049acf351e650d437"
- SHA1 for sqlite3.c: 0b34f0de356a3f21b9dfc761f3b7821b6353c570

### 2015-04-08 (3.8.9)

- Add VxWorks-7 as an officially supported and tested platform.
- Added the sqlite3_status64() interface.
- Fix memory size tracking so that it works even if SQLite uses more than 2GiB of memory.
- Added the PRAGMA index_xinfo command.
- Fix a potential 32-bit integer overflow problem in the sqlite3_blob_read() and sqlite3_blob_write() interfaces.
- Ensure that prepared statements automatically reset on extended error codes of SQLITE_BUSY and SQLITE_LOCKED even when compiled using SQLITE_OMIT_AUTORESET.
- Correct miscounts in the sqlite3_analyzer.exe utility related to WITHOUT ROWID tables.
- Added the ".dbinfo" command to the command-line shell.
- Improve the performance of fts3/4 queries that use the OR operator and at least one auxiliary fts function.
- Fix a bug in the fts3 snippet() function causing it to omit leading separator characters from snippets that begin with the first token in a column.
- SQLITE_SOURCE_ID: "2015-04-08 12:16:33 8a8ffc862e96f57aa698f93de10dee28e69f6e09"
- SHA1 for sqlite3.c: 49f1c3ae347e1327b5aaa6c7f76126bdf09c6f42

### 2015-02-25 (3.8.8.3)

- Fix a bug (ticket 2326c258d02ead33) that can lead to incorrect results if the qualifying constraint of a partial index appears in the ON clause of a LEFT JOIN.
- Added the ability to link against the "linenoise" command-line editing library in unix builds of the command-line shell.
- SQLITE_SOURCE_ID: "2015-02-25 13:29:11 9d6c1880fb75660bbabd693175579529785f8a6b"
- SHA1 for sqlite3.c: 74ee38c8c6fd175ec85a47276dfcefe8a262827a

### 2015-01-30 (3.8.8.2)

- Enhance sqlite3_wal_checkpoint_v2(TRUNCATE) interface so that it truncates the WAL file even if there is no checkpoint work to be done.
- SQLITE_SOURCE_ID: "2015-01-30 14:30:45 7757fc721220e136620a89c9d28247f28bbbc098"
- SHA1 for sqlite3.c: 85ce79948116aa9a087ec345c9d2ce2c1d3cd8af

### 2015-01-20 (3.8.8.1)

- Fix a bug in the sorting logic, present since version 3.8.4, that can cause output to appear in the wrong order on queries that contains an ORDER BY clause, a LIMIT clause, and that have approximately 60 or more columns in the result set. Ticket f97c4637102a3ae72b79.
- SQLITE_SOURCE_ID: "2015-01-20 16:51:25 f73337e3e289915a76ca96e7a05a1a8d4e890d55"
- SHA1 for sqlite3.c: 33987fb50dcc09f1429a653d6b47672f5a96f19e

### 2015-01-16 (3.8.8)

New Features:

- Added the PRAGMA data_version command that can be used to determine if a database file has been modified by another process.
- Added the SQLITE_CHECKPOINT_TRUNCATE option to the sqlite3_wal_checkpoint_v2() interface, with corresponding enhancements to PRAGMA wal_checkpoint.
- Added the sqlite3_stmt_scanstatus() interface, available only when compiled with SQLITE_ENABLE_STMT_SCANSTATUS.
- The sqlite3_table_column_metadata() is enhanced to work correctly on WITHOUT ROWID tables and to check for the existence of a a table if the column name parameter is NULL. The interface is now also included in the build by default, without requiring the SQLITE_ENABLE_COLUMN_METADATA compile-time option.
- Added the SQLITE_ENABLE_API_ARMOR compile-time option.
- Added the SQLITE_REVERSE_UNORDERED_SELECTS compile-time option.
- Added the SQLITE_SORTER_PMASZ compile-time option and SQLITE_CONFIG_PMASZ start-time option.
- Added the SQLITE_CONFIG_PCACHE_HDRSZ option to sqlite3_config() which makes it easier for applications to determine the appropriate amount of memory for use with SQLITE_CONFIG_PAGECACHE.
- The number of rows in a VALUES clause is no longer limited by SQLITE_LIMIT_COMPOUND_SELECT.
- Added the eval.c loadable extension that implements an eval() SQL function that will recursively evaluate SQL.

  Performance Enhancements:

- Reduce the number of memcpy() operations involved in balancing a b-tree, for 3.2% overall performance boost.
- Improvements to cost estimates for the skip-scan optimization.
- The automatic indexing optimization is now capable of generating a partial index if that is appropriate.

  Bug fixes:

- Ensure durability following a power loss with "PRAGMA journal_mode=TRUNCATE" by calling fsync() right after truncating the journal file.
- The query planner now recognizes that any column in the right-hand table of a LEFT JOIN can be NULL, even if that column has a NOT NULL constraint. Avoid trying to optimize out NULL tests in those cases. Fix for ticket 6f2222d550f5b0ee7ed.
- Make sure ORDER BY puts rows in ascending order even if the DISTINCT operator is implemented using a descending index. Fix for ticket c5ea805691bfc4204b1cb9e.
- Fix data races that might occur under stress when running with many threads in shared cache mode where some of the threads are opening and closing connections.
- Fix obscure crash bugs found by american fuzzy lop. Ticket a59ae93ee990a55.
- Work around a GCC optimizer bug (for gcc 4.2.1 on MacOS 10.7) that caused the R-Tree extension to compute incorrect results when compiled with -O3.

  Other changes:

- Disable the use of the strchrnul() C-library routine unless it is specifically enabled using the -DHAVE_STRCHRNULL compile-time option.
- Improvements to the effectiveness and accuracy of the likelihood(), likely(), and unlikely() SQL hint functions.
- SQLITE_SOURCE_ID: "2015-01-16 12:08:06 7d68a42face3ab14ed88407d4331872f5b243fdf"
- SHA1 for sqlite3.c: 91aea4cc722371d58aae3d22e94d2a4165276905

### 2014-12-09 (3.8.7.4)

- Bug fix: Add in a mutex that was omitted from the previous release.
- SQLITE_SOURCE_ID: "2014-12-09 01:34:36 f66f7a17b78ba617acde90fc810107f34f1a1f2e"
- SHA1 for sqlite3.c: 0a56693a3c24aa3217098afab1b6fecccdedfd23

### 2014-12-05 (3.8.7.3)

- Bug fix: Ensure the cached KeyInfo objects (an internal abstraction not visible to the application) do not go stale when operating in shared cache mode and frequently closing and reopening some database connections while leaving other database connections on the same shared cache open continuously. Ticket e4a18565a36884b00edf.
- Bug fix: Recognize that any column in the right-hand table of a LEFT JOIN can be NULL even if the column has a NOT NULL constraint. Do not apply optimizations that assume the column is never NULL. Ticket 6f2222d550f5b0ee7ed.
- SQLITE_SOURCE_ID: "2014-12-05 22:29:24 647e77e853e81a5effeb4c33477910400a67ba86"
- SHA1 for sqlite3.c: 3ad2f5ba3a4a3e3e51a1dac9fda9224b359f0261

### 2014-11-18 (3.8.7.2)

- Enhance the ROLLBACK command so that pending queries are allowed to continue as long as the schema is unchanged. Formerly, a ROLLBACK would cause all pending queries to fail with an SQLITE_ABORT or SQLITE_ABORT_ROLLBACK error. That error is still returned if the ROLLBACK modifies the schema.
- Bug fix: Make sure that NULL results from OP_Column are fully and completely NULL and do not have the MEM_Ephem bit set. Ticket 094d39a4c95ee4.
- Bug fix: The %c format in sqlite3_mprintf() is able to handle precisions greater than 70.
- Bug fix: Do not automatically remove the DISTINCT keyword from a SELECT that forms the right-hand side of an IN operator since it is necessary if the SELECT also contains a LIMIT. Ticket db87229497.
- SQLITE_SOURCE_ID: "2014-11-18 20:57:56 2ab564bf9655b7c7b97ab85cafc8a48329b27f93"
- SHA1 for sqlite3.c: b2a68d5783f48dba6a8cb50d8bf69b238c5ec53a

### 2014-10-29 (3.8.7.1)

- In PRAGMA journal_mode=TRUNCATE mode, call fsync() immediately after truncating the journal file to ensure that the transaction is durable across a power loss.
- Fix an assertion fault that can occur when updating the NULL value of a field at the end of a table that was added using ALTER TABLE ADD COLUMN.
- Do not attempt to use the strchrnul() function from the standard C library unless the HAVE_STRCHRNULL compile-time option is set.
- Fix a couple of problems associated with running an UPDATE or DELETE on a VIEW with a rowid in the WHERE clause.
- SQLITE_SOURCE_ID: "2014-10-29 13:59:56 3b7b72c4685aa5cf5e675c2c47ebec10d9704221"
- SHA1 for sqlite3.c: 2d25bd1a73dc40f538f3a81c28e6efa5999bdf0c

### 2014-10-17 (3.8.7)

Performance Enhancements:

- Many micro-optimizations result in 20.3% more work for the same number of CPU cycles relative to the previous release. The cumulative performance increase since version 3.8.0 is 61%. (Measured using cachegrind on the speedtest1.c workload on Ubuntu 13.10 x64 with gcc 4.8.1 and -Os. Your performance may vary.)
- The sorter can use auxiliary helper threads to increase real-time response. This feature is off by default and may be enabled using the PRAGMA threads command or the SQLITE_DEFAULT_WORKER_THREADS compile-time option.
- Enhance the skip-scan optimization so that it is able to skip index terms that occur in the middle of the index, not just as the left-hand side of the index.
- Improved optimization of CAST operators.
- Various improvements in how the query planner uses sqlite_stat4 information to estimate plan costs.

  New Features:

- Added new interfaces with 64-bit length parameters: sqlite3_malloc64(), sqlite3_realloc64(), sqlite3_bind_blob64(), sqlite3_result_blob64(), sqlite3_bind_text64(), and sqlite3_result_text64().
- Added the new interface sqlite3_msize() that returns the size of a memory allocation obtained from sqlite3_malloc64() and its variants.
- Added the SQLITE_LIMIT_WORKER_THREADS option to sqlite3_limit() and PRAGMA threads command for configuring the number of available worker threads.
- The spellfix1 extension allows the application to optionally specify the rowid for each INSERT.
- Added the User Authentication extension.

  Bug Fixes:

- Fix a bug in the partial index implementation that might result in an incorrect answer if a partial index is used in a subquery or in a view. Ticket 98d973b8f5.
- Fix a query planner bug that might cause a table to be scanned in the wrong direction (thus reversing the order of output) when a DESC index is used to implement the ORDER BY clause on a query that has an identical GROUP BY clause. Ticket ba7cbfaedc7e6.
- Fix a bug in sqlite3_trace() that was causing it to sometimes fail to print an SQL statement if that statement needed to be re-prepared. Ticket 11d5aa455e0d98f3c1e6a08
- Fix a faulty assert() statement. Ticket 369d57fb8e5ccdff06f1

  Test, Debug, and Analysis Changes:

- Show ASCII-art abstract syntax tree diagrams using the ".selecttrace" and ".wheretrace" commands in the command-line shell when compiled with SQLITE_DEBUG, SQLITE_ENABLE_SELECTTRACE, and SQLITE_ENABLE_WHERETRACE. Also provide the sqlite3TreeViewExpr() and sqlite3TreeViewSelect() entry points that can be invoked from with the debugger to show the parse tree when stopped at a breakpoint.
- Drop support for SQLITE_ENABLE_TREE_EXPLAIN. The SELECTTRACE mechanism provides more useful diagnostics information.
- New options to the command-line shell for configuring auxiliary memory usage: --pagecache, --lookaside, and --scratch.
- SQLITE_SOURCE_ID: "2014-10-17 11:24:17 e4ab094f8afce0817f4074e823fabe59fc29ebb4"
- SHA1 for sqlite3.c: 56dcf5e931a9e1fa12fc2d600cd91d3bf9b639cd

### 2014-08-15 (3.8.6)

- Added support for hexadecimal integer literals in the SQL parser. (Ex: 0x123abc)
- Enhanced the PRAGMA integrity_check command to detect UNIQUE and NOT NULL constraint violations.
- Increase the maximum value of SQLITE_MAX_ATTACHED from 62 to 125.
- Increase the timeout in WAL mode before issuing an SQLITE_PROTOCOL error from 1 second to 10 seconds.
- Added the likely(X) SQL function.
- The unicode61 tokenizer is now included in FTS4 by default.
- Trigger automatic reprepares on all prepared statements when ANALYZE is run.
- Added a new loadable extension source code file to the source tree: fileio.c
- Add extension functions readfile(X) and writefile(X,Y) (using code copy/pasted from fileio.c in the previous bullet) to the command-line shell.
- Added the .fullschema dot-command to the command-line shell.

  Performance Enhancements:

- Deactivate the DISTINCT keyword on subqueries on the right-hand side of the IN operator.
- Add the capability of evaluating an IN operator as a sequence of comparisons as an alternative to using a table lookup. Use the sequence of comparisons implementation in circumstances where it is likely to be faster, such as when the right-hand side of the IN operator is small and/or changes frequently.
- The query planner now uses sqlite_stat4 information (created by ANALYZE) to help determine if the skip-scan optimization is appropriate.
- Ensure that the query planner never tries to use a self-made transient index in place of a schema-defined index.
- Other minor tweaks to improve the quality of VDBE code.

  Bug Fixes:

- Fix a bug in CREATE UNIQUE INDEX, introduced when WITHOUT ROWID support added in version 3.8.2, that allows a non-unique NOT NULL column to be given a UNIQUE index. Ticket 9a6daf340df99ba93c
- Fix a bug in R-Tree extension, introduced in the previous release, that can cause an incorrect results for queries that use the rowid of the R-Tree on the left-hand side of an IN operator. Ticket d2889096e7bdeac6.
- Fix the sqlite3_stmt_busy() interface so that it gives the correct answer for ROLLBACK statements that have been stepped but never reset.
- Fix a bug in that would cause a null pointer to be dereferenced if a column with a DEFAULT that is an aggregate function tried to usee its DEFAULT. Ticket 3a88d85f36704eebe1
- CSV output from the command-line shell now always uses CRNL for the row separator and avoids inserting CR in front of NLs contained in data.
- Fix a column affinity problem with the IN operator. Ticket 9a8b09f8e6.
- Fix the ANALYZE command so that it adds correct samples for WITHOUT ROWID tables in the sqlite_stat4 table. Ticket b2fa5424e6fcb15.
- SQLITE_SOURCE_ID: "2014-08-15 11:46:33 9491ba7d738528f168657adb43a198238abde19e"
- SHA1 for sqlite3.c: 72c64f05cd9babb9c0f9b3c82536d83be7804b1c

### 2014-06-04 (3.8.5)

- Added support for partial sorting by index.
- Enhance the query planner so that it always prefers an index that uses a superset of WHERE clause terms relative to some other index.
- Improvements to the automerge command of FTS4 to better control the index size for a full-text index that is subject to a large number of updates.
- Added the sqlite3_rtree_query_callback() interface to R-Tree extension
- Added new URI query parameters "nolock" and "immutable".
- Use less memory by not remembering CHECK constraints on read-only database connections.
- Enable the OR optimization for WITHOUT ROWID tables.
- Render expressions of the form "x IN (?)" (with a single value in the list on the right-hand side of the IN operator) as if they where "x==?", Similarly optimize "x NOT IN (?)"
- Add the ".system" and ".once" commands to the command-line shell.
- Added the SQLITE_IOCAP_IMMUTABLE bit to the set of bits that can be returned by the xDeviceCharacteristics method of a VFS.
- Added the SQLITE_TESTCTRL_BYTEORDER test control.

  Bug Fixes:

- OFFSET clause ignored on queries without a FROM clause. Ticket 07d6a0453d
- Assertion fault on queries involving expressions of the form "x IN (?)". Ticket e39d032577.
- Incorrect column datatype reported. Ticket a8a0d2996a
- Duplicate row returned on a query against a table with more than 16 indices, each on a separate column, and all used via OR-connected constraints. Ticket 10fb063b11
- Partial index causes assertion fault on UPDATE OR REPLACE. Ticket 2ea3e9fe63
- Crash when calling undocumented SQL function sqlite_rename_parent() with NULL parameters. Ticket 264b970c43
- ORDER BY ignored if the query has an identical GROUP BY. Ticket b75a9ca6b0
- The group_concat(x,'') SQL function returns NULL instead of an empty string when all inputs are empty strings. Ticket 55746f9e65
- Fix a bug in the VDBE code generator that caused crashes when doing an INSERT INTO ... SELECT statement where the number of columns being inserted is larger than the number of columns in the destination table. Ticket e9654505cfd
- Fix a problem in CSV import in the command-line shell where if the leftmost field of the first row in the CSV file was both zero bytes in size and unquoted no data would be imported.
- Fix a problem in FTS4 where the left-most column that contained the notindexed column name as a prefix was not indexed rather than the column whose name matched exactly.
- Fix the sqlite3_db_readonly() interface so that it returns true if the database is read-only due to the file format write version number being too large.
- SQLITE_SOURCE_ID: "2014-06-04 14:06:34 b1ed4f2a34ba66c29b130f8d13e9092758019212"
- SHA1 for sqlite3.c: 7bc194957238c61b1a47f301270286be5bc5208c

### 2014-04-03 (3.8.4.3)

- Add a one-character fix for a problem that might cause incorrect query results on a query that mixes DISTINCT, GROUP BY in a subquery, and ORDER BY. Ticket 98825a79ce14.
- SQLITE_SOURCE_ID: "2014-04-03 16:53:12 a611fa96c4a848614efe899130359c9f6fb889c3"
- SHA1 for sqlite3.c: 310a1faeb9332a3cd8d1f53b4a2e055abf537bdc

### 2014-03-26 (3.8.4.2)

- Fix a potential buffer overread that could result when trying to search a corrupt database file.
- SQLITE_SOURCE_ID: "2014-03-26 18:51:19 02ea166372bdb2ef9d8dfbb05e78a97609673a8e"
- SHA1 for sqlite3.c: 4685ca86c2ea0649ed9f59a500013e90b3fe6d03

### 2014-03-11 (3.8.4.1)

- Work around a C-preprocessor macro conflict that breaks the build for some configurations with Microsoft Visual Studio.
- When computing the cost of the skip-scan optimization, take into account the fact that multiple seeks are required.
- SQLITE_SOURCE_ID: "2014-03-11 15:27:36 018d317b1257ce68a92908b05c9c7cf1494050d0"
- SHA1 for sqlite3.c: d5cd1535053a50aa8633725e3595740b33709ac5

### 2014-03-10 (3.8.4)

- Code optimization and refactoring for improved performance.
- Add the ".clone" and ".save" commands to the command-line shell.
- Update the banner on the command-line shell to alert novice users when they are using an ephemeral in-memory database.
- Fix editline support in the command-line shell.
- Add support for coverage testing of VDBE programs using the SQLITE_TESTCTRL_VDBE_COVERAGE verb of sqlite3_test_control().
- Update the _FILE_OFFSET_BITS macro so that builds work again on QNX.
- Change the datatype of SrcList.nSrc from type u8 to type int to work around an issue in the C compiler on AIX.
- Get extension loading working on Cygwin.
- Bug fix: Fix the char() SQL function so that it returns an empty string rather than an "out of memory" error when called with zero arguments.
- Bug fix: DISTINCT now recognizes that a zeroblob and a blob of all 0x00 bytes are the same thing. Ticket [fccbde530a]
- Bug fix: Compute the correct answer for queries that contain an IS NOT NULL term in the WHERE clause and also contain an OR term in the WHERE clause and are compiled with SQLITE_ENABLE_STAT4. Ticket [4c86b126f2]
- Bug fix: Make sure "rowid" columns are correctly resolved in joins between normal tables and WITHOUT ROWID tables. Ticket [c34d0557f7]
- Bug fix: Make sure the same temporary registers are not used in concurrent co-routines used to implement compound SELECT statements containing ORDER BY clauses, as such use can lead to incorrect answers. Ticket [8c63ff0eca]
- Bug fix: Ensure that "ORDER BY random()" clauses do not get optimized out. Ticket [65bdeb9739]
- Bug fix: Repair a name-resolution error that can occur in sub-select statements contained within a TRIGGER. Ticket [4ef7e3cfca]
- Bug fix: Fix column default values expressions of the form "DEFAULT(-(-9223372036854775808))" so that they work correctly, initializing the column to a floating point value approximately equal to +9223372036854775808.0.
- SQLITE_SOURCE_ID: "2014-03-10 12:20:37 530a1ee7dc2435f80960ce4710a3c2d2bfaaccc5"
- SHA1 for sqlite3.c: b0c22e5f15f5ba2afd017ecd990ea507918afe1c

### 2014-02-11 (3.8.3.1)

- Fix a bug (ticket 4c86b126f2) that causes rows to go missing on some queries with OR clauses and IS NOT NULL operators in the WHERE clause, when the SQLITE_ENABLE_STAT3 or SQLITE_ENABLE_STAT4 compile-time options are used.
- Fix a harmless compiler warning that was causing problems for VS2013.
- SQLITE_SOURCE_ID: "2014-02-11 14:52:19 ea3317a4803d71d88183b29f1d3086f46d68a00e"
- SHA1 for sqlite3.c: 990004ef2d0eec6a339e4caa562423897fe02bf0

### 2014-02-03 (3.8.3)

- Added support for common table expressions and the WITH clause.
- Added the printf() SQL function.
- Added SQLITE_DETERMINISTIC as an optional bit in the 4th argument to the sqlite3_create_function() and related interfaces, providing applications with the ability to create new functions that can be factored out of inner loops when they have constant arguments.
- Add SQLITE_READONLY_DBMOVED error code, returned at the beginning of a transaction, to indicate that the underlying database file has been renamed or moved out from under SQLite.
- Allow arbitrary expressions, including function calls and subqueries, in the filename argument to ATTACH.
- Allow a VALUES clause to be used anywhere a SELECT statement is valid.
- Reseed the PRNG used by sqlite3_randomness(N,P) when invoked with N==0. Automatically reseed after a fork() on unix.
- Enhance the spellfix1 virtual table so that it can search efficiently by rowid.
- Performance enhancements.
- Improvements to the comments in the VDBE byte-code display when running EXPLAIN.
- Add the "%token_class" directive to LEMON parser generator and use it to simplify the grammar.
- Change the LEMON source code to avoid calling C-library functions that OpenBSD considers dangerous. (Ex: sprintf).
- Bug fix: In the command-line shell CSV import feature, do not end a field when an escaped double-quote occurs at the end of a CRLN line.
- SQLITE_SOURCE_ID: "2014-02-03 13:52:03 e816dd924619db5f766de6df74ea2194f3e3b538"
- SHA1 for sqlite3.c: 98a07da78f71b0275e8d9c510486877adc31dbee

### 2013-12-06 (3.8.2)

- Changed the defined behavior for the CAST expression when floating point values greater than +9223372036854775807 are cast into into integers so that the result is the largest possible integer, +9223372036854775807, instead of the smallest possible integer, -9223372036854775808. After this change, CAST(9223372036854775809.0 as INT) yields +9223372036854775807 instead of -9223372036854775808. ← Potentially Incompatible Change!
- Added support for WITHOUT ROWID tables.
- Added the skip-scan optimization to the query planner.
- Extended the virtual table interface, and in particular the sqlite3_index_info object to allow a virtual table to report its estimate on the number of rows that will be returned by a query.
- Update the R-Tree extension to make use of the enhanced virtual table interface.
- Add the SQLITE_ENABLE_EXPLAIN_COMMENTS compile-time option.
- Enhanced the comments that are inserted into EXPLAIN output when the SQLITE_ENABLE_EXPLAIN_COMMENTS compile-time option is enabled.
- Performance enhancements in the VDBE, especially to the OP_Column opcode.
- Factor constant subexpressions in inner loops out to the initialization code in prepared statements.
- Enhanced the ".explain" output formatting of the command-line shell so that loops are indented to better show the structure of the program.
- Enhanced the ".timer" feature of the command-line shell so that it shows wall-clock time in addition to system and user times.
- SQLITE_SOURCE_ID: "2013-12-06 14:53:30 27392118af4c38c5203a04b8013e1afdb1cebd0d"
- SHA1 for sqlite3.c: 6422c7d69866f5ea3db0968f67ee596e7114544e

### 2013-10-17 (3.8.1)

- Added the unlikely() and likelihood() SQL functions to be used as hints to the query planner.
- Enhancements to the query planner:
  - Take into account the fact WHERE clause terms that cannot be used with indices still probably reduce the number of output rows.
  - Estimate the sizes of table and index rows and use the smallest applicable B-Tree for full scans and "count(*)" operations.
- Added the soft_heap_limit pragma.
- Added support for SQLITE_ENABLE_STAT4
- Added support for "sz=NNN" parameters at the end of sqlite_stat1.stat fields used to specify the average length in bytes for table and index rows.
- Avoid running foreign-key constraint checks on an UPDATE if none of the modified columns are associated with foreign keys.
- Added the SQLITE_MINIMUM_FILE_DESCRIPTOR compile-time option
- Added the win32-longpath VFS on windows, permitting filenames up to 32K characters in length.
- The Date And Time Functions are enhanced so that the current time (ex: julianday('now')) is always the same for multiple function invocations within the same sqlite3_step() call.
- Add the "totype.c" extension, implementing the tointeger() and toreal() SQL functions.
- FTS4 queries are better able to make use of docid<$limit constraints to limit the amount of I/O required.
- Added the hidden fts4aux languageid column to the fts4aux virtual table.
- The VACUUM command packs the database about 1% tighter.
- The sqlite3_analyzer utility program is updated to provide better descriptions and to compute a more accurate estimate for "Non-sequential pages"
- Refactor the implementation of PRAGMA statements to improve parsing performance.
- The directory used to hold temporary files on unix can now be set using the SQLITE_TMPDIR environment variable, which takes precedence over the TMPDIR environment variable. The sqlite3_temp_directory global variable still has higher precedence than both environment variables, however.
- Added the PRAGMA stats statement.
- Bug fix: Return the correct answer for "SELECT count(*) FROM table" even if there is a partial index on the table. Ticket a5c8ed66ca.
- SQLITE_SOURCE_ID: "2013-10-17 12:57:35 c78be6d786c19073b3a6730dfe3fb1be54f5657a"
- SHA1 for sqlite3.c: 0a54d76566728c2ba96292a49b138e4f69a7c391

### 2013-09-03 (3.8.0.2)

- Fix a bug in the optimization that attempts to omit unused LEFT JOINs
- SQLITE_SOURCE_ID: "2013-09-03 17:11:13 7dd4968f235d6e1ca9547cda9cf3bd570e1609ef"
- SHA1 for sqlite3.c: 6cf0c7b46975a87a0dc3fba69c229a7de61b0c21

### 2013-08-29 (3.8.0.1)

- Fix an off-by-one error that caused quoted empty string at the end of a CRNL-terminated line of CSV input to be misread by the command-line shell.
- Fix a query planner bug involving a LEFT JOIN with a BETWEEN or LIKE/GLOB constraint and then another INNER JOIN to the right that involves an OR constraint.
- Fix a query planner bug that could result in a segfault when querying tables with a UNIQUE or PRIMARY KEY constraint with more than four columns.
- SQLITE_SOURCE_ID: "2013-08-29 17:35:01 352362bc01660edfbda08179d60f09e2038a2f49"
- SHA1 for sqlite3.c: 99906bf63e6cef63d6f3d7f8526ac4a70e76559e

### 2013-08-26 (3.8.0)

- Add support for partial indexes
- Cut-over to the next generation query planner for faster and better query plans.
- The EXPLAIN QUERY PLAN output no longer shows an estimate of the number of rows generated by each loop in a join.
- Added the FTS4 notindexed option, allowing non-indexed columns in an FTS4 table.
- Added the SQLITE_STMTSTATUS_VM_STEP option to sqlite3_stmt_status().
- Added the cache_spill pragma.
- Added the query_only pragma.
- Added the defer_foreign_keys pragma and the sqlite3_db_status(db, SQLITE_DBSTATUS_DEFERRED_FKS,...) C-language interface.
- Added the "percentile()" function as a loadable extension in the ext/misc subdirectory of the source tree.
- Added the SQLITE_ALLOW_URI_AUTHORITY compile-time option.
- Add the sqlite3_cancel_auto_extension(X) interface.
- A running SELECT statement that lacks a FROM clause (or any other statement that never reads or writes from any database file) will not prevent a read transaction from closing.
- Add the SQLITE_DEFAULT_AUTOMATIC_INDEX compile-time option. Setting this option to 0 disables automatic indices by default.
- Issue an SQLITE_WARNING_AUTOINDEX warning on the SQLITE_CONFIG_LOG whenever the query planner uses an automatic index.
- Added the SQLITE_FTS3_MAX_EXPR_DEPTH compile-time option.
- Added an optional 5th parameter defining the collating sequence to the next_char() extension SQL function.
- The SQLITE_BUSY_SNAPSHOT extended error code is returned in WAL mode when a read transaction cannot be upgraded to a write transaction because the read is on an older snapshot.
- Enhancements to the sqlite3_analyzer utility program to provide size information separately for each individual index of a table, in addition to the aggregate size.
- Allow read transactions to be freely opened and closed by SQL statements run from within the implementation of application-defined SQL functions if the function is called by a SELECT statement that does not access any database table.
- Disable the use of posix_fallocate() on all (unix) systems unless the HAVE_POSIX_FALLOCATE compile-time option is used.
- Update the ".import" command in the command-line shell to support multi-line fields and correct RFC-4180 quoting and to issue warning and/or error messages if the input text is not strictly RFC-4180 compliant.
- Bug fix: In the unicode61 tokenizer of FTS4, treat all private code points as identifier symbols.
- Bug fix: Bare identifiers in ORDER BY clauses bind more tightly to output column names, but identifiers in expressions bind more tightly to input column names. Identifiers in GROUP BY clauses always prefer output column names, however.
- Bug fixes: Multiple problems in the legacy query optimizer were fixed by the move to NGQP.
- SQLITE_SOURCE_ID: "2013-08-26 04:50:08 f64cd21e2e23ed7cff48f7dafa5e76adde9321c2"
- SHA1 for sqlite3.c: b7347f4b4c2a840e6ba12040093d606bd16ea21e

### 2013-05-20 (3.7.17)

- Add support for memory-mapped I/O.
- Add the sqlite3_strglob() convenience interface.
- Assigned the integer at offset 68 in the database header as the Application ID for when SQLite is used as an application file-format. Added the PRAGMA application_id command to query and set the Application ID.
- Report rollback recovery in the error log as SQLITE_NOTICE_RECOVER_ROLLBACK. Change the error log code for WAL recover from SQLITE_OK to SQLITE_NOTICE_RECOVER_WAL.
- Report the risky uses of unlinked database files and database filename aliasing as SQLITE_WARNING messages in the error log.
- Added the SQLITE_TRACE_SIZE_LIMIT compile-time option.
- Increase the default value of SQLITE_MAX_SCHEMA_RETRY to 50 and make sure that it is honored in every place that a schema change might force a statement retry.
- Add a new test harness called "mptester" used to verify correct operation when multiple processes are using the same database file at the same time.
- Enhance the extension loading mechanism to be more flexible (while still maintaining backwards compatibility) in two ways:
  1. If the default entry point "sqlite3_extension_init" is not present in the loadable extension, also try an entry point "sqlite3_X_init" where "X" is based on the shared library filename. This allows every extension to have a different entry point, which allows them to be statically linked with no code changes.
  2. The shared library filename passed to sqlite3_load_extension() may omit the filename suffix, and an appropriate architecture-dependent suffix (".so", ".dylib", or ".dll") will be added automatically.
- Added many new loadable extensions to the source tree, including amatch, closure, fuzzer, ieee754, nextchar, regexp, spellfix, and wholenumber. See header comments on each extension source file for further information about what that extension does.
- Enhance FTS3 to avoid using excess stack space when there are a huge number of terms on the right-hand side of the MATCH operator. A side-effect of this change is that the MATCH operator can only accommodate 12 NEAR operators at a time.
- Enhance the fts4aux virtual table so that it can be a TEMP table.
- Added the fts3tokenize virtual table to the full-text search logic.
- Query planner enhancement: Use the transitive property of constraints to move constraints into the outer loops of a join whenever possible, thereby reducing the amount of work that needs to occur in inner loops.
- Discontinue the use of posix_fallocate() on unix, as it does not work on all filesystems.
- Improved tracing and debugging facilities in the Windows VFS.
- Bug fix: Fix a potential database corruption bug in shared cache mode when one database connection is closed while another is in the middle of a write transaction. Ticket e636a050b7
- Bug fix: Only consider AS names from the result set as candidates for resolving identifiers in the WHERE clause if there are no other matches. In the ORDER BY clause, AS names take priority over any column names. Ticket 2500cdb9be05
- Bug fix: Do not allow a virtual table to cancel the ORDER BY clause unless all outer loops are guaranteed to return no more than one row result. Ticket ba82a4a41eac1.
- Bug fix: Do not suppress the ORDER BY clause on a virtual table query if an IN constraint is used. Ticket f69b96e3076e.
- Bug fix: The command-line shell gives an exit code of 0 when terminated using the ".quit" command.
- Bug fix: Make sure PRAGMA statements appear in sqlite3_trace() output.
- Bug fix: When a compound query that uses an ORDER BY clause with a COLLATE operator, make sure that the sorting occurs according to the specified collation and that the comparisons associate with the compound query use the native collation. Ticket 6709574d2a8d8.
- Bug fix: Makes sure the authorizer callback gets a valid pointer to the string "ROWID" for the column-name parameter when doing an UPDATE that changes the rowid. Ticket 0eb70d77cb05bb2272
- Bug fix: Do not move WHERE clause terms inside OR expressions that are contained within an ON clause of a LEFT JOIN. Ticket f2369304e4
- Bug fix: Make sure an error is always reported when attempting to preform an operation that requires a collating sequence that is missing. Ticket 0fc59f908b
- SQLITE_SOURCE_ID: "2013-05-20 00:56:22 118a3b35693b134d56ebd780123b7fd6f1497668"
- SHA1 for sqlite3.c: 246987605d0503c700a08b9ee99a6b5d67454aab

### 2013-04-12 (3.7.16.2)

- Fix a bug (present since version 3.7.13) that could result in database corruption on windows if two or more processes try to access the same database file at the same time and immediately after third process crashed in the middle of committing to that same file. See ticket 7ff3120e4f for further information.
- SQLITE_SOURCE_ID: "2013-04-12 11:52:43 cbea02d93865ce0e06789db95fd9168ebac970c7"
- SHA1 for sqlite3.c: d466b54789dff4fb0238b9232e74896deaefab94

### 2013-03-29 (3.7.16.1)

- Fix for a bug in the ORDER BY optimizer that was introduced in version 3.7.15 which would sometimes optimize out the sorting step when in fact the sort was required. Ticket a179fe7465
- Fix a long-standing bug in the CAST expression that would recognize UTF16 characters as digits even if their most-significant-byte was not zero. Ticket 689137afb6da41.
- Fix a bug in the NEAR operator of FTS3 when applied to subfields. Ticket 38b1ae018f.
- Fix a long-standing bug in the storage engine that would (very rarely) cause a spurious report of an SQLITE_CORRUPT error but which was otherwise harmless. Ticket 6bfb98dfc0c.
- The SQLITE_OMIT_MERGE_SORT option has been removed. The merge sorter is now a required component of SQLite.
- Fixed lots of spelling errors in the source-code comments
- SQLITE_SOURCE_ID: "2013-03-29 13:44:34 527231bc67285f01fb18d4451b28f61da3c4e39d"
- SHA1 for sqlite3.c: 7a91ceceac9bcf47ceb8219126276e5518f7ff5a

### 2013-03-18 (3.7.16)

- Added the PRAGMA foreign_key_check command.
- Added new extended error codes for all SQLITE_CONSTRAINT errors
- Added the SQLITE_READONLY_ROLLBACK extended error code for when a database cannot be opened because it needs rollback recovery but is read-only.
- Added SQL functions unicode(A) and char(X1,...,XN).
- Performance improvements for PRAGMA incremental_vacuum, especially in cases where the number of free pages is greater than what will fit on a single trunk page of the freelist.
- Improved optimization of queries containing aggregate min() or max().
- Enhance virtual tables so that they can potentially use an index when the WHERE clause contains the IN operator.
- Allow indices to be used for sorting even if prior terms of the index are constrained by IN operators in the WHERE clause.
- Enhance the PRAGMA table_info command so that the "pk" column is an increasing integer to show the order of columns in the primary key.
- Enhance the query optimizer to exploit transitive join constraints.
- Performance improvements in the query optimizer.
- Allow the error message from PRAGMA integrity_check to be longer than 20000 bytes.
- Improved name resolution for deeply nested queries.
- Added the test_regexp.c module as a demonstration of how to implement the REGEXP operator.
- Improved error messages in the RTREE extension.
- Enhance the command-line shell so that a non-zero argument to the ".exit" command causes the shell to exit immediately without cleanly shutting down the database connection.
- Improved error messages for invalid boolean arguments to dot-commands in the command-line shell.
- Improved error messages for "foreign key mismatch" showing the names of the two tables involved.
- Remove all uses of umask() in the unix VFS.
- Added the PRAGMA vdbe_addoptrace and PRAGMA vdbe_debug commands.
- Change to use strncmp() or the equivalent instead of memcmp() when comparing non-zero-terminated strings.
- Update cygwin interfaces to omit deprecated API calls.
- Enhance the spellfix1 extension so that the edit distance cost table can be changed at runtime by inserting a string like 'edit_cost_table=TABLE' into the "command" field.
- Bug fix: repair a long-standing problem that could cause incorrect query results in a 3-way or larger join that compared INTEGER fields against TEXT fields in two or more places. Ticket fc7bd6358f
- Bug fix: Issue an error message if the 16-bit reference counter on a view overflows due to an overly complex query.
- Bug fix: Avoid leaking memory on LIMIT and OFFSET clauses in deeply nested UNION ALL queries.
- Bug fix: Make sure the schema is up-to-date prior to running pragmas table_info, index_list, index_info, and foreign_key_list.
- SQLITE_SOURCE_ID: "2013-03-18 11:39:23 66d5f2b76750f3520eb7a495f6247206758f5b90"
- SHA1 for sqlite3.c: 7308ab891ca1b2ebc596025cfe4dc36f1ee89cf6

### 2013-01-09 (3.7.15.2)

- Fix a bug, introduced in version 3.7.15, that causes an ORDER BY clause to be optimized out of a three-way join when the ORDER BY is actually required. Ticket 598f5f7596b055
- SQLITE_SOURCE_ID: "2013-01-09 11:53:05 c0e09560d26f0a6456be9dd3447f5311eb4f238f"
- SHA1 for sqlite3.c: 5741f47d1bc38aa0a8c38f09e60a5fe0031f272d

### 2012-12-19 (3.7.15.1)

- Fix a bug, introduced in version 3.7.15, that causes a segfault if the AS name of a result column of a SELECT statement is used as a logical term in the WHERE clause. Ticket a7b7803e8d1e869.
- SQLITE_SOURCE_ID: "2012-12-19 20:39:10 6b85b767d0ff7975146156a99ad673f2c1a23318"
- SHA1 for sqlite3.c: bbbaa68061e925bd4d7d18d7e1270935c5f7e39a

### 2012-12-12 (3.7.15)

- Added the sqlite3_errstr() interface.
- Avoid invoking the sqlite3_trace() callback multiple times when a statement is automatically reprepared due to SQLITE_SCHEMA errors.
- Added support for Windows Phone 8 platforms
- Enhance IN operator processing to make use of indices with numeric affinities.
- Do full-table scans using covering indices when possible, under the theory that an index will be smaller and hence can be scanned with less I/O.
- Enhance the query optimizer so that ORDER BY clauses are more aggressively optimized, especially in joins where various terms of the ORDER BY clause come from separate tables of the join.
- Add the ability to implement FROM clause subqueries as coroutines rather that manifesting the subquery into a temporary table.
- Enhancements the command-line shell:
  - Added the ".print" command
  - Negative numbers in the ".width" command cause right-alignment
  - Add the ".wheretrace" command when compiled with SQLITE_DEBUG
- Added the busy_timeout pragma.
- Added the instr() SQL function.
- Added the SQLITE_FCNTL_BUSYHANDLER file control, used to allow VFS implementations to get access to the busy handler callback.
- The xDelete method in the built-in VFSes now return SQLITE_IOERR_DELETE_NOENT if the file to be deleted does not exist.
- Enhanced support for QNX.
- Work around an optimizer bug in the MSVC compiler when targeting ARM.
- Bug fix: Avoid various concurrency problems in shared cache mode.
- Bug fix: Avoid a deadlock or crash if the backup API, shared cache, and the SQLite Encryption Extension are all used at once.
- Bug fix: SQL functions created using the TCL interface honor the "nullvalue" setting.
- Bug fix: Fix a 32-bit overflow problem on CREATE INDEX for databases larger than 16GB.
- Bug fix: Avoid segfault when using the COLLATE operator inside of a CHECK constraint or view in shared cache mode.
- SQLITE_SOURCE_ID: "2012-12-12 13:36:53 cd0b37c52658bfdf992b1e3dc467bae1835a94ae"
- SHA1 for sqlite3.c: 2b413611f5e3e3b6ef5f618f2a9209cdf25cbcff"

### 2012-10-04 (3.7.14.1)

- Fix a bug (ticket [d02e1406a58ea02d]]) that causes a segfault on a LEFT JOIN that includes an OR in the ON clause.
- Work around a bug in the optimizer in the VisualStudio-2012 compiler that causes invalid code to be generated when compiling SQLite on ARM.
- Fix the TCL interface so that the "nullvalue" setting is honored for TCL implementations of SQL functions.
- SQLITE_SOURCE_ID: "2012-10-04 19:37:12 091570e46d04e84b67228e0bdbcd6e1fb60c6bdb"
- SHA1 for sqlite3.c: 62aaecaacab3a4bf4a8fe4aec1cfdc1571fe9a44

### 2012-09-03 (3.7.14)

- Drop built-in support for OS/2. If you need to upgrade an OS/2 application to use this or a later version of SQLite, then add an application-defined VFS using the sqlite3_vfs_register() interface. The code removed in this release can serve as a baseline for the application-defined VFS.
- Ensure that floating point values are preserved exactly when reconstructing a database from the output of the ".dump" command of the command-line shell.
- Added the sqlite3_close_v2() interface.
- Updated the command-line shell so that it can be built using SQLITE_OMIT_FLOATING_POINT and SQLITE_OMIT_AUTOINIT.
- Improvements to the windows makefiles and build processes.
- Enhancements to PRAGMA integrity_check and PRAGMA quick_check so that they can optionally check just a single attached database instead of all attached databases.
- Enhancements to WAL mode processing that ensure that at least one valid read-mark is available at all times, so that read-only processes can always read the database.
- Performance enhancements in the sorter used by ORDER BY and CREATE INDEX.
- Added the SQLITE_DISABLE_FTS4_DEFERRED compile-time option.
- Better handling of aggregate queries where the aggregate functions are contained within subqueries.
- Enhance the query planner so that it will try to use a covering index on queries that make use of or optimization.
- SQLITE_SOURCE_ID: "2012-09-03 15:42:36 c0d89d4a9752922f9e367362366efde4f1b06f2a"
- SHA1 for sqlite3.c: 5fdf596b29bb426001f28b488ff356ae14d5a5a6

### 2012-06-11 (3.7.13)

- In-memory databases that are specified using URI filenames are allowed to use shared cache, so that the same in-memory database can be accessed from multiple database connections.
- Recognize and use the mode=memory query parameter in URI filenames.
- Avoid resetting the schema of shared cache connections when any one connection closes. Instead, wait for the last connection to close before resetting the schema.
- In the RTREE extension, when rounding 64-bit floating point numbers to 32-bit for storage, always round in a direction that causes the bounding box to get larger.
- Adjust the unix driver to avoid unnecessary calls to fchown().
- Add interfaces sqlite3_quota_ferror() and sqlite3_quota_file_available() to the test_quota.c module.
- The sqlite3_create_module() and sqlite3_create_module_v2() interfaces return SQLITE_MISUSE on any attempt to overload or replace a virtual table module. The destructor is always called in this case, in accordance with historical and current documentation.
- SQLITE_SOURCE_ID: "2012-06-11 02:05:22 f5b5a13f7394dc143aa136f1d4faba6839eaa6dc"
- SHA1 for sqlite3.c: ff0a771d6252545740ba9685e312b0e3bb6a641b

### 2012-05-22 (3.7.12.1)

- Fix a bug (ticket c2ad16f997) in the 3.7.12 release that can cause a segfault for certain obscure nested aggregate queries.
- Fix various other minor test script problems.
- SQLITE_SOURCE_ID: "2012-05-22 02:45:53 6d326d44fd1d626aae0e8456e5fa2049f1ce0789"
- SHA1 for sqlite3.c: d494e8d81607f0515d4f386156fb0fd86d5ba7df

### 2012-05-14 (3.7.12)

- Add the SQLITE_DBSTATUS_CACHE_WRITE option for sqlite3_db_status().
- Optimize the typeof() and length() SQL functions so that they avoid unnecessary reading of database content from disk.
- Add the FTS4 "merge" command, the FTS4 "automerge" command, and the FTS4 "integrity-check" command.
- Report the name of specific CHECK constraints that fail.
- In the command-line shell, use popen() instead of fopen() if the first character of the argument to the ".output" command is "|".
- Make use of OVERLAPPED in the windows VFS to avoid some system calls and thereby obtain a performance improvement.
- More aggressive optimization of the AND operator when one side or the other is always false.
- Improved performance of queries with many OR-connected terms in the WHERE clause that can all be indexed.
- Add the SQLITE_RTREE_INT_ONLY compile-time option to force the R*Tree Extension Module to use integer instead of floating point values for both storage and computation.
- Enhance the PRAGMA integrity_check command to use much less memory when processing multi-gigabyte databases.
- New interfaces added to the test_quota.c add-on module.
- Added the ".trace" dot-command to the command-line shell.
- Allow virtual table constructors to be invoked recursively.
- Improved optimization of ORDER BY clauses on compound queries.
- Improved optimization of aggregate subqueries contained within an aggregate query.
- Bug fix: Fix the RELEASE command so that it does not cancel pending queries. This repairs a problem introduced in 3.7.11.
- Bug fix: Do not discard the DISTINCT as superfluous unless a subset of the result set is subject to a UNIQUE constraint and it none of the columns in that subset can be NULL. Ticket 385a5b56b9.
- Bug fix: Do not optimize away an ORDER BY clause that has the same terms as a UNIQUE index unless those terms are also NOT NULL. Ticket 2a5629202f.
- SQLITE_SOURCE_ID: "2012-05-14 01:41:23 8654aa9540fe9fd210899d83d17f3f407096c004"
- SHA1 for sqlite3.c: 57e2104a0f7b3f528e7f6b7a8e553e2357ccd2e1

### 2012-03-20 (3.7.11)

- Enhance the INSERT syntax to allow multiple rows to be inserted via the VALUES clause.
- Enhance the CREATE VIRTUAL TABLE command to support the IF NOT EXISTS clause.
- Added the sqlite3_stricmp() interface as a counterpart to sqlite3_strnicmp().
- Added the sqlite3_db_readonly() interface.
- Added the SQLITE_FCNTL_PRAGMA file control, giving VFS implementations the ability to add new PRAGMA statements or to override built-in PRAGMAs.
- Queries of the form: "SELECT max(x), y FROM table" returns the value of y on the same row that contains the maximum x value.
- Added support for the FTS4 languageid option.
- Documented support for the FTS4 content option. This feature has actually been in the code since version 3.7.9 but is only now considered to be officially supported.
- Pending statements no longer block ROLLBACK. Instead, the pending statement will return SQLITE_ABORT upon next access after the ROLLBACK.
- Improvements to the handling of CSV inputs in the command-line shell
- Fix a bug introduced in version 3.7.10 that might cause a LEFT JOIN to be incorrectly converted into an INNER JOIN if the WHERE clause indexable terms connected by OR.
- SQLITE_SOURCE_ID: "2012-03-20 11:35:50 00bb9c9ce4f465e6ac321ced2a9d0062dc364669"
- SHA1 for sqlite3.c: d460d7eda3a9dccd291aed2a9fda868b9b120a10

### 2012-01-16 (3.7.10)

- The default schema format number is changed from 1 to 4. This means that, unless the PRAGMA legacy_file_format=ON statement is run, newly created database files will be unreadable by version of SQLite prior to 3.3.0 (2006-01-10). It also means that the descending indices are enabled by default.
- The sqlite3_pcache_methods structure and the SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE configuration parameters are deprecated. They are replaced by a new sqlite3_pcache_methods2 structure and SQLITE_CONFIG_PCACHE2 and SQLITE_CONFIG_GETPCACHE2 configuration parameters.
- Added the powersafe overwrite property to the VFS interface. Provide the SQLITE_IOCAP_POWERSAFE_OVERWRITE I/O capability, the SQLITE_POWERSAFE_OVERWRITE compile-time option, and the "psow=BOOLEAN" query parameter for URI filenames.
- Added the sqlite3_db_release_memory() interface and the shrink_memory pragma.
- Added the sqlite3_db_filename() interface.
- Added the sqlite3_stmt_busy() interface.
- Added the sqlite3_uri_boolean() and sqlite3_uri_int64() interfaces.
- If the argument to PRAGMA cache_size is negative N, that means to use approximately -1024*N bytes of memory for the page cache regardless of the page size.
- Enhanced the default memory allocator to make use of _msize() on windows, malloc_size() on Mac, and malloc_usable_size() on Linux.
- Enhanced the query planner to support index queries with range constraints on the rowid.
- Enhanced the query planner flattening logic to allow UNION ALL compounds to be promoted upwards to replace a simple wrapper SELECT even if the compounds are joins.
- Enhanced the query planner so that the xfer optimization can be used with INTEGER PRIMARY KEY ON CONFLICT as long as the destination table is initially empty.
- Enhanced the windows VFS so that all system calls can be overridden using the xSetSystemCall interface.
- Updated the "unix-dotfile" VFS to use locking directories with mkdir() and rmdir() instead of locking files with open() and unlink().
- Enhancements to the test_quota.c extension to support stdio-like interfaces with quotas.
- Change the unix VFS to be tolerant of read() system calls that return less then the full number of requested bytes.
- Change both unix and windows VFSes to report a sector size of 4096 instead of the old default of 512.
- In the TCL Interface, add the -uri option to the "sqlite3" TCL command used for creating new database connection objects.
- Added the SQLITE_TESTCTRL_EXPLAIN_STMT test-control option with the SQLITE_ENABLE_TREE_EXPLAIN compile-time option to enable the command-line shell to display ASCII-art parse trees of SQL statements that it processes, for debugging and analysis.
- Bug fix: Add an additional xSync when restarting a WAL in order to prevent an exceedingly unlikely but theoretically possible database corruption following power-loss. Ticket ff5be73dee.
- Bug fix: Change the VDBE so that all registers are initialized to Invalid instead of NULL. Ticket 7bbfb7d442
- Bug fix: Fix problems that can result from 32-bit integer overflow. Ticket ac00f496b7e2
- SQLITE_SOURCE_ID: "2012-01-16 13:28:40 ebd01a8deffb5024a5d7494eef800d2366d97204"
- SHA1 for sqlite3.c: 6497cbbaad47220bd41e2e4216c54706e7ae95d4

### 2011-11-01 (3.7.9)

- If a search token (on the right-hand side of the MATCH operator) in FTS4 begins with "^" then that token must be the first in its field of the document. ** Potentially Incompatible Change **
- Added options SQLITE_DBSTATUS_CACHE_HIT and SQLITE_DBSTATUS_CACHE_MISS to the sqlite3_db_status() interface.
- Removed support for SQLITE_ENABLE_STAT2, replacing it with the much more capable SQLITE_ENABLE_STAT3 option.
- Enhancements to the sqlite3_analyzer utility program, including the --pageinfo and --stats options and support for multiplexed databases.
- Enhance the sqlite3_data_count() interface so that it can be used to determine if SQLITE_DONE has been seen on the prepared statement.
- Added the SQLITE_FCNTL_OVERWRITE file-control by which the SQLite core indicates to the VFS that the current transaction will overwrite the entire database file.
- Increase the default lookaside memory allocator allocation size from 100 to 128 bytes.
- Enhanced the query planner so that it can factor terms in and out of OR expressions in the WHERE clause in an effort to find better indices.
- Added the SQLITE_DIRECT_OVERFLOW_READ compile-time option, causing overflow pages to be read directly from the database file, bypassing the page cache.
- Remove limits on the magnitude of precision and width value in the format specifiers of the sqlite3_mprintf() family of string rendering routines.
- Fix a bug that prevent ALTER TABLE ... RENAME from working on some virtual tables in a database with a UTF16 encoding.
- Fix a bug in ASCII-to-float conversion that causes slow performance and incorrect results when converting numbers with ridiculously large exponents.
- Fix a bug that causes incorrect results in aggregate queries that use multiple aggregate functions whose arguments contain complicated expressions that differ only in the case of string literals contained within those expressions.
- Fix a bug that prevented the page_count and quick_check pragmas from working correctly if their names were capitalized.
- Fix a bug that caused VACUUM to fail if the count_changes pragma was engaged.
- Fix a bug in virtual table implementation that causes a crash if an FTS4 table is dropped inside a transaction and a SAVEPOINT occurs afterwards.
- SQLITE_SOURCE_ID: "2011-11-01 00:52:41 c7c6050ef060877ebe77b41d959e9df13f8c9b5e"
- SHA1 for sqlite3.c: becd16877f4f9b281b91c97e106089497d71bb47

### 2011-09-19 (3.7.8)

- Orders of magnitude performance improvement for CREATE INDEX on very large tables.
- Improved the windows VFS to better defend against interference from anti-virus software.
- Improved query plan optimization when the DISTINCT keyword is present.
- Allow more system calls to be overridden in the unix VFS - to provide better support for chromium sandboxes.
- Increase the default size of a lookahead cache line from 100 to 128 bytes.
- Enhancements to the test_quota.c module so that it can track preexisting files.
- Bug fix: Virtual tables now handle IS NOT NULL constraints correctly.
- Bug fixes: Correctly handle nested correlated subqueries used with indices in a WHERE clause.
- SQLITE_SOURCE_ID: "2011-09-19 14:49:19 3e0da808d2f5b4d12046e05980ca04578f581177"
- SHA1 for sqlite3.c: bfcd74a655636b592c5dba6d0d5729c0f8e3b4de

### 2011-06-28 (3.7.7.1)

- Fix a bug causing PRAGMA case_sensitive_like statements compiled using sqlite3_prepare() to fail with an SQLITE_SCHEMA error.
- SQLITE_SOURCE_ID: "2011-06-28 17:39:05 af0d91adf497f5f36ec3813f04235a6e195a605f"
- SHA1 for sqlite3.c: d47594b8a02f6cf58e91fb673e96cb1b397aace0

### 2011-06-23 (3.7.7)

- Add support for URI filenames
- Add the sqlite3_vtab_config() interface in support of ON CONFLICT clauses with virtual tables.
- Add the xSavepoint, xRelease and xRollbackTo methods in virtual tables in support of SAVEPOINT for virtual tables.
- Update the built-in FTS3/FTS4 and RTREE virtual tables to support ON CONFLICT clauses and REPLACE.
- Avoid unnecessary reparsing of the database schema.
- Added support for the FTS4 prefix option and the FTS4 order option.
- Allow WAL-mode databases to be opened read-only as long as there is an existing read/write connection.
- Added support for short filenames.
- SQLITE_SOURCE_ID: "2011-06-23 19:49:22 4374b7e83ea0a3fbc3691f9c0c936272862f32f2"
- SHA1 for sqlite3.c: 5bbe79e206ae5ffeeca760dbd0d66862228db551

### 2011-05-19 (3.7.6.3)

- Fix a problem with WAL mode which could cause transactions to silently rollback if the cache_size is set very small (less than 10) and SQLite comes under memory pressure.

### 2011-04-17 (3.7.6.2)

- Fix the function prototype for the open(2) system call to agree with POSIX. Without this fix, pthreads does not work correctly on NetBSD.
- SQLITE_SOURCE_ID: "2011-04-17 17:25:17 154ddbc17120be2915eb03edc52af1225eb7cb5e"
- SHA1 for sqlite3.c: 806577fd524dd5f3bfd8d4d27392ed2752bc9701

### 2011-04-13 (3.7.6.1)

- Fix a bug in 3.7.6 that only appears if the SQLITE_FCNTL_SIZE_HINT file control is used with a build of SQLite that makes use of the HAVE_POSIX_FALLOCATE compile-time option and which has SQLITE_ENABLE_LOCKING_MODE turned off.
- SQLITE_SOURCE_ID: "2011-04-13 14:40:25 a35e83eac7b185f4d363d7fa51677f2fdfa27695"
- SHA1 for sqlite3.c: b81bfa27d3e09caf3251475863b1ce6dd9f6ab66

### 2011-04-12 (3.7.6)

- Added the sqlite3_wal_checkpoint_v2() interface and enhanced the wal_checkpoint pragma to support blocking checkpoints.
- Improvements to the query planner so that it makes better estimates of plan costs and hence does a better job of choosing the right plan, especially when SQLITE_ENABLE_STAT2 is used.
- Fix a bug which prevented deferred foreign key constraints from being enforced when sqlite3_finalize() was not called by one statement with a failed foreign key constraint prior to another statement with foreign key constraints running.
- Integer arithmetic operations that would have resulted in overflow are now performed using floating-point instead.
- Increased the version number on the VFS object to 3 and added new methods xSetSysCall, xGetSysCall, and xNextSysCall used for doing full-coverage testing.
- Increase the maximum value of SQLITE_MAX_ATTACHED from 30 to 62 (though the default value remains at 10).
- Enhancements to FTS4:
  1. Added the fts4aux table
  2. Added support for compressed FTS4 content
- Enhance the ANALYZE command to support the name of an index as its argument, in order to analyze just that one index.
- Added the "unix-excl" built-in VFS on unix and unix-like platforms.
- SQLITE_SOURCE_ID: "2011-04-12 01:58:40 f9d43fa363d54beab6f45db005abac0a7c0c47a7"
- SHA1 for sqlite3.c: f38df08547efae0ff4343da607b723f588bbd66b

### 2011-02-01 (3.7.5)

- Added the sqlite3_vsnprintf() interface.
- Added the SQLITE_DBSTATUS_LOOKASIDE_HIT, SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE, and SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL options for the sqlite3_db_status() interface.
- Added the SQLITE_OMIT_AUTORESET compile-time option.
- Added the SQLITE_DEFAULT_FOREIGN_KEYS compile-time option.
- Updates to sqlite3_stmt_readonly() so that its result is well-defined for all prepared statements and so that it works with VACUUM.
- Added the "-heap" option to the command-line shell
- Fix a bug involving frequent changes in and out of WAL mode and VACUUM that could (in theory) cause database corruption.
- Enhance the sqlite3_trace() mechanism so that nested SQL statements such as might be generated by virtual tables are shown but are shown in comments and without parameter expansion. This greatly improves tracing output when using the FTS3/4 and/or RTREE virtual tables.
- Change the xFileControl() methods on all built-in VFSes to return SQLITE_NOTFOUND instead of SQLITE_ERROR for an unrecognized operation code.
- The SQLite core invokes the SQLITE_FCNTL_SYNC_OMITTED file control to the VFS in place of a call to xSync if the database has PRAGMA synchronous set to OFF.

### 2010-12-07 (3.7.4)

- Added the sqlite3_blob_reopen() interface to allow an existing sqlite3_blob object to be rebound to a new row.
- Use the new sqlite3_blob_reopen() interface to improve the performance of FTS.
- VFSes that do not support shared memory are allowed to access WAL databases if PRAGMA locking_mode is set to EXCLUSIVE.
- Enhancements to EXPLAIN QUERY PLAN.
- Added the sqlite3_stmt_readonly() interface.
- Added PRAGMA checkpoint_fullfsync.
- Added the SQLITE_FCNTL_FILE_POINTER option to sqlite3_file_control().
- Added support for FTS4 and enhancements to the FTS matchinfo() function.
- Added the test_superlock.c module which provides example code for obtaining an exclusive lock to a rollback or WAL database.
- Added the test_multiplex.c module which provides an example VFS that provides multiplexing (sharding) of a DB, splitting it over multiple files of fixed size.
- A very obscure bug associated with the or optimization was fixed.

### 2010-10-08 (3.7.3)

- Added the sqlite3_create_function_v2() interface that includes a destructor callback.
- Added support for custom r-tree queries using application-supplied callback routines to define the boundary of the query region.
- The default page cache strives more diligently to avoid using memory beyond what is allocated to it by SQLITE_CONFIG_PAGECACHE. Or if using page cache is allocating from the heap, it strives to avoid going over the sqlite3_soft_heap_limit64(), even if SQLITE_ENABLE_MEMORY_MANAGEMENT is not set.
- Added the sqlite3_soft_heap_limit64() interface as a replacement for sqlite3_soft_heap_limit().
- The ANALYZE command now gathers statistics on tables even if they have no indices.
- Tweaks to the query planner to help it do a better job of finding the most efficient query plan for each query.
- Enhanced the internal text-to-numeric conversion routines so that they work with UTF8 or UTF16, thereby avoiding some UTF16-to-UTF8 text conversions.
- Fix a problem that was causing excess memory usage with large WAL transactions in win32 systems.
- The interface between the VDBE and B-Tree layer is enhanced such that the VDBE provides hints to the B-Tree layer letting the B-Tree layer know when it is safe to use hashing instead of B-Trees for transient tables.
- Miscellaneous documentation enhancements.

### 2010-08-24 (3.7.2)

- Fix an old and very obscure bug that can lead to corruption of the database free-page list when incremental_vacuum is used.

### 2010-08-23 (3.7.1)

- Added new commands SQLITE_DBSTATUS_SCHEMA_USED and SQLITE_DBSTATUS_STMT_USED to the sqlite3_db_status() interface, in order to report out the amount of memory used to hold the schema and prepared statements of a connection.
- Increase the maximum size of a database pages from 32KiB to 64KiB.
- Use the LIKE optimization even if the right-hand side string contains no wildcards.
- Added the SQLITE_FCNTL_CHUNK_SIZE verb to the sqlite3_file_control() interface for both unix and windows, to cause database files to grow in large chunks in order to reduce disk fragmentation.
- Fixed a bug in the query planner that caused performance regressions relative to 3.6.23.1 on some complex joins.
- Fixed a typo in the OS/2 backend.
- Refactored the pager module.
- The SQLITE_MAX_PAGE_SIZE compile-time option is now silently ignored. The maximum page size is hard-coded at 65536 bytes.

### 2010-08-04 (3.7.0.1)

- Fix a potential database corruption bug that can occur if version 3.7.0 and version 3.6.23.1 alternately write to the same database file. Ticket [51ae9cad317a1]
- Fix a performance regression related to the query planner enhancements of version 3.7.0.

### 2010-07-21 (3.7.0)

- Added support for write-ahead logging.
- Query planner enhancement - automatic transient indices are created when doing so reduces the estimated query time.
- Query planner enhancement - the ORDER BY becomes a no-op if the query also contains a GROUP BY clause that forces the correct output order.
- Add the SQLITE_DBSTATUS_CACHE_USED verb for sqlite3_db_status().
- The logical database size is now stored in the database header so that bytes can be appended to the end of the database file without corrupting it and so that SQLite will work correctly on systems that lack support for ftruncate().

### 2010-03-26 (3.6.23.1)

- Fix a bug in the offsets() function of FTS3
- Fix a missing "sync" that when omitted could lead to database corruption if a power failure or OS crash occurred just as a ROLLBACK operation was finishing.

### 2010-03-09 (3.6.23)

- Added the secure_delete pragma.
- Added the sqlite3_compileoption_used() and sqlite3_compileoption_get() interfaces as well as the compile_options pragma and the sqlite_compileoption_used() and sqlite_compileoption_get() SQL functions.
- Added the sqlite3_log() interface together with the SQLITE_CONFIG_LOG verb to sqlite3_config(). The ".log" command is added to the Command Line Interface.
- Improvements to FTS3.
- Improvements and bug-fixes in support for SQLITE_OMIT_FLOATING_POINT.
- The integrity_check pragma is enhanced to detect out-of-order rowids.
- The ".genfkey" operator has been removed from the Command Line Interface.
- Updates to the co-hosted Lemon LALR(1) parser generator. (These updates did not affect SQLite.)
- Various minor bug fixes and performance enhancements.

### 2010-01-06 (3.6.22)

- Fix bugs that can (rarely) lead to incorrect query results when the CAST or OR operators are used in the WHERE clause of a query.
- Continuing enhancements and improvements to FTS3.
- Other miscellaneous bug fixes.

### 2009-12-07 (3.6.21)

- The SQL output resulting from sqlite3_trace() is now modified to include the values of bound parameters.
- Performance optimizations targeting a specific use case from a single high-profile user of SQLite. A 12% reduction in the number of CPU operations is achieved (as measured by Valgrind). Actual performance improvements in practice may vary depending on workload. Changes include:
  - The ifnull() and coalesce() SQL functions are now implemented using in-line VDBE code rather than calling external functions, so that unused arguments need never be evaluated.
  - The substr() SQL function does not bother to measure the length its entire input string if it is only computing a prefix
  - Unnecessary OP_IsNull, OP_Affinity, and OP_MustBeInt VDBE opcodes are suppressed
  - Various code refactorizations for performance
- The FTS3 extension has undergone a major rework and cleanup. New FTS3 documentation is now available.
- The SQLITE_SECURE_DELETE compile-time option fixed to make sure that content is deleted even when the truncate optimization applies.
- Improvements to "dot-command" handling in the Command Line Interface.
- Other minor bug fixes and documentation enhancements.

### 2009-11-04 (3.6.20)

- Optimizer enhancement: prepared statements are automatically re-compiled when a binding on the RHS of a LIKE operator changes or when any range constraint changes under SQLITE_ENABLE_STAT2.
- Various minor bug fixes and documentation enhancements.

### 2009-10-30 (3.6.16.1)

- A small patch to version 3.6.16 to fix the OP_If bug.

### 2009-10-14 (3.6.19)

- Added support for foreign key constraints. Foreign key constraints are disabled by default. Use the foreign_keys pragma to turn them on.
- Generalized the IS and IS NOT operators to take arbitrary expressions on their right-hand side.
- The TCL Interface has been enhanced to use the Non-Recursive Engine (NRE) interface to the TCL interpreter when linked against TCL 8.6 or later.
- Fix a bug introduced in 3.6.18 that can lead to a segfault when an attempt is made to write on a read-only database.

### 2009-09-11 (3.6.18)

- Versioning of the SQLite source code has transitioned from CVS to Fossil.
- Query planner enhancements.
- The SQLITE_ENABLE_STAT2 compile-time option causes the ANALYZE command to collect a small histogram of each index, to help SQLite better select among competing range query indices.
- Recursive triggers can be enabled using the PRAGMA recursive_triggers statement.
- Delete triggers fire when rows are removed due to a REPLACE conflict resolution. This feature is only enabled when recursive triggers are enabled.
- Added the SQLITE_OPEN_SHAREDCACHE and SQLITE_OPEN_PRIVATECACHE flags for sqlite3_open_v2() used to override the global shared cache mode settings for individual database connections.
- Added improved version identification features: C-Preprocessor macro SQLITE_SOURCE_ID, C/C++ interface sqlite3_sourceid(), and SQL function sqlite_source_id().
- Obscure bug fix on triggers ([efc02f9779]).

### 2009-08-10 (3.6.17)

- Expose the sqlite3_strnicmp() interface for use by extensions and applications.
- Remove the restriction on virtual tables and shared cache mode. Virtual tables and shared cache can now be used at the same time.
- Many code simplifications and obscure bug fixes in support of providing 100% branch test coverage.

### 2009-06-27 (3.6.16)

- Fix a bug (ticket #3929) that occasionally causes INSERT or UPDATE operations to fail on an indexed table that has a self-modifying trigger.
- Other minor bug fixes and performance optimizations.

### 2009-06-15 (3.6.15)

- Refactor the internal representation of SQL expressions so that they use less memory on embedded platforms.
- Reduce the amount of stack space used
- Fix an 64-bit alignment bug on HP/UX and Sparc
- The sqlite3_create_function() family of interfaces now return SQLITE_MISUSE instead of SQLITE_ERROR when passed invalid parameter combinations.
- When new tables are created using CREATE TABLE ... AS SELECT ... the datatype of the columns is the simplified SQLite datatype (TEXT, INT, REAL, NUMERIC, or BLOB) instead of a copy of the original datatype from the source table.
- Resolve race conditions when checking for a hot rollback journal.
- The sqlite3_shutdown() interface frees all mutexes under windows.
- Enhanced robustness against corrupt database files
- Continuing improvements to the test suite and fixes to obscure bugs and inconsistencies that the test suite improvements are uncovering.

### 2009-05-25 (3.6.14.2)

- Fix a code generator bug introduced in version 3.6.14. This bug can cause incorrect query results under obscure circumstances. Ticket #3879.

### 2009-05-19 (3.6.14.1)

- Fix a bug in group_concat(), ticket #3841
- Fix a performance bug in the pager cache, ticket #3844
- Fix a bug in the sqlite3_backup implementation that can lead to a corrupt backup database. Ticket #3858.

### 2009-05-07 (3.6.14)

- Added the optional asynchronous VFS module.
- Enhanced the query optimizer so that virtual tables are able to make use of OR and IN operators in the WHERE clause.
- Speed improvements in the btree and pager layers.
- Added the SQLITE_HAVE_ISNAN compile-time option which will cause the isnan() function from the standard math library to be used instead of SQLite's own home-brew NaN checker.
- Countless minor bug fixes, documentation improvements, new and improved test cases, and code simplifications and cleanups.

### 2009-04-13 (3.6.13)

- Fix a bug in version 3.6.12 that causes a segfault when running a count(*) on the sqlite_master table of an empty database. Ticket #3774.
- Fix a bug in version 3.6.12 that causes a segfault that when inserting into a table using a DEFAULT value where there is a function as part of the DEFAULT value expression. Ticket #3791.
- Fix data structure alignment issues on Sparc. Ticket #3777.
- Other minor bug fixes.

### 2009-03-31 (3.6.12)

- Fixed a bug that caused database corruption when an incremental_vacuum is rolled back in an in-memory database. Ticket #3761.
- Added the sqlite3_unlock_notify() interface.
- Added the reverse_unordered_selects pragma.
- The default page size on windows is automatically adjusted to match the capabilities of the underlying filesystem.
- Add the new ".genfkey" command in the CLI for generating triggers to implement foreign key constraints.
- Performance improvements for "count(*)" queries.
- Reduce the amount of heap memory used, especially by TRIGGERs.

### 2009-02-18 (3.6.11)

- Added the hot-backup interface.
- Added new commands ".backup" and ".restore" to the CLI.
- Added new methods backup and restore to the TCL interface.
- Improvements to the syntax bubble diagrams
- Various minor bug fixes

### 2009-01-15 (3.6.10)

- Fix a cache coherency problem that could lead to database corruption. Ticket #3584.

### 2009-01-14 (3.6.9)

- Fix two bugs, which when combined might result in incorrect query results. Both bugs were harmless by themselves; only when they team up do they cause problems. Ticket #3581.

### 2009-01-12 (3.6.8)

- Added support for nested transactions
- Enhanced the query optimizer so that it is able to use multiple indices to efficiently process OR-connected constraints in a WHERE clause.
- Added support for parentheses in FTS3 query patterns using the SQLITE_ENABLE_FTS3_PARENTHESIS compile-time option.

### 2008-12-16 (3.6.7)

- Reorganize the Unix interface in os_unix.c
- Added support for "Proxy Locking" on Mac OS X.
- Changed the prototype of the sqlite3_auto_extension() interface in a way that is backwards compatible but which might cause warnings in new builds of applications that use that interface.
- Changed the signature of the xDlSym method of the sqlite3_vfs object in a way that is backwards compatible but which might cause compiler warnings.
- Added superfluous casts and variable initializations in order to suppress nuisance compiler warnings.
- Fixes for various minor bugs.

### 2008-11-26 (3.6.6.2)

- Fix a bug in the b-tree delete algorithm that seems like it might be able to cause database corruption. The bug was first introduced in version 3.6.6 by check-in [5899] on 2008-11-13.
- Fix a memory leak that can occur following a disk I/O error.

### 2008-11-22 (3.6.6.1)

- Fix a bug in the page cache that can lead database corruption following a rollback. This bug was first introduced in version 3.6.4.
- Two other very minor bug fixes

### 2008-11-19 (3.6.6)

- Fix a #define that prevented memsys5 from compiling
- Fix a problem in the virtual table commit mechanism that was causing a crash in FTS3. Ticket #3497.
- Add the application-defined page cache
- Added built-in support for VxWorks

### 2008-11-12 (3.6.5)

- Add the MEMORY option to the journal_mode pragma.
- Added the sqlite3_db_mutex() interface.
- Added the SQLITE_OMIT_TRUNCATE_OPTIMIZATION compile-time option.
- Fixed the truncate optimization so that sqlite3_changes() and sqlite3_total_changes() interfaces and the count_changes pragma return the correct values.
- Added the sqlite3_extended_errcode() interface.
- The COMMIT command now succeeds even if there are pending queries. It returns SQLITE_BUSY if there are pending incremental BLOB I/O requests.
- The error code is changed to SQLITE_BUSY (instead of SQLITE_ERROR) when an attempt is made to ROLLBACK while one or more queries are still pending.
- Drop all support for the experimental memory allocators memsys4 and memsys6.
- Added the SQLITE_ZERO_MALLOC compile-time option.

### 2008-10-15 (3.6.4)

- Add option support for LIMIT and ORDER BY clauses on DELETE and UPDATE statements. Only works if SQLite is compiled with SQLITE_ENABLE_UPDATE_DELETE_LIMIT.
- Added the sqlite3_stmt_status() interface for performance monitoring.
- Add the INDEXED BY clause.
- The LOCKING_STYLE extension is now enabled by default on Mac OS X
- Added the TRUNCATE option to PRAGMA journal_mode
- Performance enhancements to tree balancing logic in the B-Tree layer.
- Added the source code and documentation for the genfkey program for automatically generating triggers to enforce foreign key constraints.
- Added the SQLITE_OMIT_TRUNCATE_OPTIMIZATION compile-time option.
- The SQL language documentation is converted to use syntax diagrams instead of BNF.
- Other minor bug fixes

### 2008-09-22 (3.6.3)

- Fix for a bug in the SELECT DISTINCT logic that was introduced by the prior version.
- Other minor bug fixes

### 2008-08-30 (3.6.2)

- Split the pager subsystem into separate pager and pcache subsystems.
- Factor out identifier resolution procedures into separate files.
- Bug fixes

### 2008-08-06 (3.6.1)

- Added the lookaside memory allocator for a speed improvement in excess of 15% on some workloads. (Your mileage may vary.)
- Added the SQLITE_CONFIG_LOOKASIDE verb to sqlite3_config() to control the default lookaside configuration.
- Added verbs SQLITE_STATUS_PAGECACHE_SIZE and SQLITE_STATUS_SCRATCH_SIZE to the sqlite3_status() interface.
- Modified SQLITE_CONFIG_PAGECACHE and SQLITE_CONFIG_SCRATCH to remove the "+4" magic number in the buffer size computation.
- Added the sqlite3_db_config() and sqlite3_db_status() interfaces for controlling and monitoring the lookaside allocator separately on each database connection.
- Numerous other performance enhancements
- Miscellaneous minor bug fixes

### 2008-07-16 (3.6.0 beta)

- Modifications to the virtual file system interface to support a wider range of embedded systems. See 35to36.html for additional information. *** Potentially incompatible change ***
- All C-preprocessor macros used to control compile-time options now begin with the prefix "SQLITE_". This may require changes to applications that compile SQLite using their own makefiles and with custom compile-time options, hence we mark this as a *** Potentially incompatible change ***
- The SQLITE_MUTEX_APPDEF compile-time option is no longer supported. Alternative mutex implementations can now be added at run-time using the sqlite3_config() interface with the SQLITE_CONFIG_MUTEX verb. *** Potentially incompatible change ***
- The handling of IN and NOT IN operators that contain a NULL on their right-hand side expression is brought into compliance with the SQL standard and with other SQL database engines. This is a bug fix, but as it has the potential to break legacy applications that depend on the older buggy behavior, we mark that as a *** Potentially incompatible change ***
- The result column names generated for compound subqueries have been simplified to show only the name of the column of the original table and omit the table name. This makes SQLite operate more like other SQL database engines.
- Added the sqlite3_config() interface for doing run-time configuration of the entire SQLite library.
- Added the sqlite3_status() interface used for querying run-time status information about the overall SQLite library and its subsystems.
- Added the sqlite3_initialize() and sqlite3_shutdown() interfaces.
- The SQLITE_OPEN_NOMUTEX option was added to sqlite3_open_v2().
- Added the PRAGMA page_count command.
- Added the sqlite3_next_stmt() interface.
- Added a new R*Tree virtual table

### 2008-05-14 (3.5.9)

- Added experimental support for the journal_mode PRAGMA and persistent journal.
- Journal mode PERSIST is the default behavior in exclusive locking mode.
- Fix a performance regression on LEFT JOIN (see ticket #3015) that was mistakenly introduced in version 3.5.8.
- Performance enhancement: Reengineer the internal routines used to interpret and render variable-length integers.
- Fix a buffer-overrun problem in sqlite3_mprintf() which occurs when a string without a zero-terminator is passed to "%.*s".
- Always convert IEEE floating point NaN values into NULL during processing. (Ticket #3060)
- Make sure that when a connection blocks on a RESERVED lock that it is able to continue after the lock is released. (Ticket #3093)
- The "configure" scripts should now automatically configure Unix systems for large file support. Improved error messages for when large files are encountered and large file support is disabled.
- Avoid cache pages leaks following disk-full or I/O errors
- And, many more minor bug fixes and performance enhancements....

### 2008-04-16 (3.5.8)

- Expose SQLite's internal pseudo-random number generator (PRNG) via the sqlite3_randomness() interface
- New interface sqlite3_context_db_handle() that returns the database connection handle that has invoked an application-defined SQL function.
- New interface sqlite3_limit() allows size and length limits to be set on a per-connection basis and at run-time.
- Improved crash-robustness: write the database page size into the rollback journal header.
- Allow the VACUUM command to change the page size of a database file.
- The xAccess() method of the VFS is allowed to return -1 to signal a memory allocation error.
- Performance improvement: The OP_IdxDelete opcode uses unpacked records, obviating the need for one OP_MakeRecord opcode call for each index record deleted.
- Performance improvement: Constant subexpressions are factored out of loops.
- Performance improvement: Results of OP_Column are reused rather than issuing multiple OP_Column opcodes.
- Fix a bug in the RTRIM collating sequence.
- Fix a bug in the SQLITE_SECURE_DELETE option that was causing Firefox crashes. Make arrangements to always test SQLITE_SECURE_DELETE prior to each release.
- Other miscellaneous performance enhancements.
- Other miscellaneous minor bug fixes.

### 2008-03-17 (3.5.7)

- Fix a bug (ticket #2927) in the register allocation for compound selects - introduced by the new VM code in version 3.5.5.
- ALTER TABLE uses double-quotes instead of single-quotes for quoting filenames.
- Use the WHERE clause to reduce the size of a materialized VIEW in an UPDATE or DELETE statement. (Optimization)
- Do not apply the flattening optimization if the outer query is an aggregate and the inner query contains ORDER BY. (Ticket #2943)
- Additional OS/2 updates
- Added an experimental power-of-two, first-fit memory allocator.
- Remove all instances of sprintf() from the code
- Accept "Z" as the zulu timezone at the end of date strings
- Fix a bug in the LIKE optimizer that occurs when the last character before the first wildcard is an upper-case "Z"
- Added the "bitvec" object for keeping track of which pages have been journalled. Improves speed and reduces memory consumption, especially for large database files.
- Get the SQLITE_ENABLE_LOCKING_STYLE macro working again on Mac OS X.
- Store the statement journal in the temporary file directory instead of collocated with the database file.
- Many improvements and cleanups to the configure script

### 2008-02-06 (3.5.6)

- Fix a bug (ticket #2913) that prevented virtual tables from working in a LEFT JOIN. The problem was introduced into shortly before the 3.5.5 release.
- Bring the OS/2 porting layer up-to-date.
- Add the new sqlite3_result_error_code() API and use it in the implementation of ATTACH so that proper error codes are returned when an ATTACH fails.

### 2008-01-31 (3.5.5)

- Convert the underlying virtual machine to be a register-based machine rather than a stack-based machine. The only user-visible change is in the output of EXPLAIN.
- Add the build-in RTRIM collating sequence.

### 2007-12-14 (3.5.4)

- Fix a critical bug in UPDATE or DELETE that occurs when an OR REPLACE clause or a trigger causes rows in the same table to be deleted as side effects. (See ticket #2832.) The most likely result of this bug is a segmentation fault, though database corruption is a possibility.
- Bring the processing of ORDER BY into compliance with the SQL standard for case where a result alias and a table column name are in conflict. Correct behavior is to prefer the result alias. Older versions of SQLite incorrectly picked the table column. (See ticket #2822.)
- The VACUUM command preserves the setting of the legacy_file_format pragma. (Ticket #2804.)
- Productize and officially support the group_concat() SQL function.
- Better optimization of some IN operator expressions.
- Add the ability to change the auto_vacuum status of a database by setting the auto_vaccum pragma and VACUUMing the database.
- Prefix search in FTS3 is much more efficient.
- Relax the SQL statement length restriction in the CLI so that the ".dump" output of databases with very large BLOBs and strings can be played back to recreate the database.
- Other small bug fixes and optimizations.

### 2007-11-27 (3.5.3)

- Move website and documentation files out of the source tree into a separate CM system.
- Fix a long-standing bug in INSERT INTO ... SELECT ... statements where the SELECT is compound.
- Fix a long-standing bug in RAISE(IGNORE) as used in BEFORE triggers.
- Fixed the operator precedence for the ~ operator.
- On Win32, do not return an error when attempting to delete a file that does not exist.
- Allow collating sequence names to be quoted.
- Modify the TCL interface to use sqlite3_prepare_v2().
- Fix multiple bugs that can occur following a malloc() failure.
- sqlite3_step() returns SQLITE_MISUSE instead of crashing when called with a NULL parameter.
- FTS3 now uses the SQLite memory allocator exclusively. The FTS3 amalgamation can now be appended to the SQLite amalgamation to generate a super-amalgamation containing both.
- The DISTINCT keyword now will sometimes use an INDEX if an appropriate index is available and the optimizer thinks its use might be advantageous.

### 2007-11-05 (3.5.2)

- Dropped support for the SQLITE_OMIT_MEMORY_ALLOCATION compile-time option.
- Always open files using FILE_FLAG_RANDOM_ACCESS under Windows.
- The 3rd parameter of the built-in SUBSTR() function is now optional.
- Bug fix: do not invoke the authorizer when reparsing the schema after a schema change.
- Added the experimental malloc-free memory allocator in mem3.c.
- Virtual machine stores 64-bit integer and floating point constants in binary instead of text for a performance boost.
- Fix a race condition in test_async.c.
- Added the ".timer" command to the CLI

### 2007-10-04 (3.5.1)

- Nota Bene: We are not using terms "alpha" or "beta" on this release because the code is stable and because if we use those terms, nobody will upgrade. However, we still reserve the right to make incompatible changes to the new VFS interface in future releases.
- Fix a bug in the handling of SQLITE_FULL errors that could lead to database corruption. Ticket #2686.
- The test_async.c drive now does full file locking and works correctly when used simultaneously by multiple processes on the same database.
- The CLI ignores whitespace (including comments) at the end of lines
- Make sure the query optimizer checks dependencies on all terms of a compound SELECT statement. Ticket #2640.
- Add demonstration code showing how to build a VFS for a raw mass storage without a filesystem.
- Added an output buffer size parameter to the xGetTempname() method of the VFS layer.
- Sticky SQLITE_FULL or SQLITE_IOERR errors in the pager are reset when a new transaction is started.

### 2007-09-04 (3.5.0) alpha

- Redesign the OS interface layer. See 34to35.html for details. *** Potentially incompatible change ***
- The sqlite3_release_memory(), sqlite3_soft_heap_limit(), and sqlite3_enable_shared_cache() interfaces now work cross all threads in the process, not just the single thread in which they are invoked. *** Potentially incompatible change ***
- Added the sqlite3_open_v2() interface.
- Reimplemented the memory allocation subsystem and made it replaceable at compile-time.
- Created a new mutex subsystem and made it replicable at compile-time.
- The same database connection may now be used simultaneously by separate threads.

### 2007-08-13 (3.4.2)

- Fix a database corruption bug that might occur if a ROLLBACK command is executed in auto-vacuum mode and a very small sqlite3_soft_heap_limit is set. Ticket #2565.
- Add the ability to run a full regression test with a small sqlite3_soft_heap_limit.
- Fix other minor problems with using small soft heap limits.
- Work-around for GCC bug 32575.
- Improved error detection of misused aggregate functions.
- Improvements to the amalgamation generator script so that all symbols are prefixed with either SQLITE_PRIVATE or SQLITE_API.

### 2007-07-20 (3.4.1)

- Fix a bug in VACUUM that can lead to database corruption if two processes are connected to the database at the same time and one VACUUMs then the other then modifies the database.
- The expression "+column" is now considered the same as "column" when computing the collating sequence to use on the expression.
- In the TCL language interface, "@variable" instead of "$variable" always binds as a blob.
- Added PRAGMA freelist_count for determining the current size of the freelist.
- The PRAGMA auto_vacuum=incremental setting is now persistent.
- Add FD_CLOEXEC to all open files under Unix.
- Fix a bug in the min()/max() optimization when applied to descending indices.
- Make sure the TCL language interface works correctly with 64-bit integers on 64-bit machines.
- Allow the value -9223372036854775808 as an integer literal in SQL statements.
- Add the capability of "hidden" columns in virtual tables.
- Use the macro SQLITE_PRIVATE (defaulting to "static") on all internal functions in the amalgamation.
- Add pluggable tokenizers and ICU tokenization support to FTS2
- Other minor bug fixes and documentation enhancements

### 2007-06-18 (3.4.0)

- Fix a bug that can lead to database corruption if an SQLITE_BUSY error occurs in the middle of an explicit transaction and that transaction is later committed. Ticket #2409. See the CorruptionFollowingBusyError wiki page for details.
- Fix a bug that can lead to database corruption if autovacuum mode is on and a malloc() failure follows a CREATE TABLE or CREATE INDEX statement which itself follows a cache overflow inside a transaction. See ticket #2418.
- Added explicit upper bounds on the sizes and quantities of things SQLite can process. This change might cause compatibility problems for applications that use SQLite in the extreme, which is why the current release is 3.4.0 instead of 3.3.18.
- Added support for Incremental BLOB I/O.
- Added the sqlite3_bind_zeroblob() API and the zeroblob() SQL function.
- Added support for Incremental Vacuum.
- Added the SQLITE_MIXED_ENDIAN_64BIT_FLOAT compile-time option to support ARM7 processors with goofy endianness.
- Removed all instances of sprintf() and strcpy() from the core library.
- Added support for International Components for Unicode (ICU) to the full-text search extensions.

- In the Windows OS driver, reacquire a SHARED lock if an attempt to acquire an EXCLUSIVE lock fails. Ticket #2354
- Fix the REPLACE() function so that it returns NULL if the second argument is an empty string. Ticket #2324.
- Document the hazards of type conversions in sqlite3_column_blob() and related APIs. Fix unnecessary type conversions. Ticket #2321.
- Internationalization of the TRIM() function. Ticket #2323
- Use memmove() instead of memcpy() when moving between memory regions that might overlap. Ticket #2334
- Fix an optimizer bug involving subqueries in a compound SELECT that has both an ORDER BY and a LIMIT clause. Ticket #2339.
- Make sure the sqlite3_snprintf() interface does not zero-terminate the buffer if the buffer size is less than 1. Ticket #2341
- Fix the built-in printf logic so that it prints "NaN" not "Inf" for floating-point NaNs. Ticket #2345
- When converting BLOB to TEXT, use the text encoding of the main database. Ticket #2349
- Keep the full precision of integers (if possible) when casting to NUMERIC. Ticket #2364
- Fix a bug in the handling of UTF16 codepoint 0xE000
- Consider explicit collate clauses when matching WHERE constraints to indices in the query optimizer. Ticket #2391
- Fix the query optimizer to correctly handle constant expressions in the ON clause of a LEFT JOIN. Ticket #2403
- Fix the query optimizer to handle rowid comparisons to NULL correctly. Ticket #2404
- Fix many potential segfaults that could be caused by malicious SQL statements.

### 2007-04-25 (3.3.17)

- When the "write_version" value of the database header is larger than what the library understands, make the database read-only instead of unreadable.
- Other minor bug fixes

### 2007-04-18 (3.3.16)

- Fix a bug that caused VACUUM to fail if NULLs appeared in a UNIQUE column.
- Reinstate performance improvements that were added in Version 3.3.14 but regressed in Version 3.3.15.
- Fix problems with the handling of ORDER BY expressions on compound SELECT statements in subqueries.
- Fix a potential segfault when destroying locks on WinCE in a multi-threaded environment.
- Documentation updates.

### 2007-04-09 (3.3.15)

- Fix a bug introduced in 3.3.14 that caused a rollback of CREATE TEMP TABLE to leave the database connection wedged.
- Fix a bug that caused an extra NULL row to be returned when a descending query was interrupted by a change to the database.
- The FOR EACH STATEMENT clause on a trigger now causes a syntax error. It used to be silently ignored.
- Fix an obscure and relatively harmless problem that might have caused a resource leak following an I/O error.
- Many improvements to the test suite. Test coverage now exceeded 98%

### 2007-04-02 (3.3.14)

- Fix a bug (ticket #2273) that could cause a segfault when the IN operator is used one one term of a two-column index and the right-hand side of the IN operator contains a NULL.
- Added a new OS interface method for determining the sector size of underlying media: sqlite3OsSectorSize().
- A new algorithm for statements of the form INSERT INTO table1 SELECT * FROM table2 is faster and reduces fragmentation. VACUUM uses statements of this form and thus runs faster and defragments better.
- Performance enhancements through reductions in disk I/O:
  - Do not read the last page of an overflow chain when deleting the row - just add that page to the freelist.
  - Do not store pages being deleted in the rollback journal.
  - Do not read in the (meaningless) content of pages extracted from the freelist.
  - Do not flush the page cache (and thus avoiding a cache refill) unless another process changes the underlying database file.
  - Truncate rather than delete the rollback journal when committing a transaction in exclusive access mode, or when committing the TEMP database.
- Added support for exclusive access mode using "PRAGMA locking_mode=EXCLUSIVE"
- Use heap space instead of stack space for large buffers in the pager - useful on embedded platforms with stack-space limitations.
- Add a makefile target "sqlite3.c" that builds an amalgamation containing the core SQLite library C code in a single file.
- Get the library working correctly when compiled with GCC option "-fstrict-aliasing".
- Removed the vestigal SQLITE_PROTOCOL error.
- Improvements to test coverage, other minor bugs fixed, memory leaks plugged, code refactored and/or recommended in places for easier reading.

### 2007-02-13 (3.3.13)

- Add a "fragmentation" measurement in the output of sqlite3_analyzer.
- Add the COLLATE operator used to explicitly set the collating sequence used by an expression. This feature is considered experimental pending additional testing.
- Allow up to 64 tables in a join - the old limit was 32.
- Added two new experimental functions: randomBlob() and hex(). Their intended use is to facilitate generating UUIDs.
- Fix a problem where PRAGMA count_changes was causing incorrect results for updates on tables with triggers
- Fix a bug in the ORDER BY clause optimizer for joins where the left-most table in the join is constrained by a UNIQUE index.
- Fixed a bug in the "copy" method of the TCL interface.
- Bug fixes in fts1 and fts2 modules.

### 2007-01-27 (3.3.12)

- Fix another bug in the IS NULL optimization that was added in version 3.3.9.
- Fix an assertion fault that occurred on deeply nested views.
- Limit the amount of output that PRAGMA integrity_check generates.
- Minor syntactic changes to support a wider variety of compilers.

### 2007-01-22 (3.3.11)

- Fix another bug in the implementation of the new sqlite3_prepare_v2() API. We'll get it right eventually...
- Fix a bug in the IS NULL optimization that was added in version 3.3.9 - the bug was causing incorrect results on certain LEFT JOINs that included in the WHERE clause an IS NULL constraint for the right table of the LEFT JOIN.
- Make AreFileApisANSI() a no-op macro in WinCE since WinCE does not support this function.

### 2007-01-09 (3.3.10)

- Fix bugs in the implementation of the new sqlite3_prepare_v2() API that can lead to segfaults.
- Fix 1-second round-off errors in the strftime() function
- Enhance the Windows OS layer to provide detailed error codes
- Work around a win2k problem so that SQLite can use single-character database file names
- The user_version and schema_version pragmas correctly set their column names in the result set
- Documentation updates

### 2007-01-04 (3.3.9)

- Fix bugs in pager.c that could lead to database corruption if two processes both try to recover a hot journal at the same instant
- Added the sqlite3_prepare_v2() API.
- Fixed the ".dump" command in the command-line shell to show indices, triggers and views again.
- Change the table_info pragma so that it returns NULL for the default value if there is no default value
- Support for non-ASCII characters in win95 filenames
- Query optimizer enhancements:
  - Optimizer does a better job of using indices to satisfy ORDER BY clauses that sort on the integer primary key
  - Use an index to satisfy an IS NULL operator in the WHERE clause
  - Fix a bug that was causing the optimizer to miss an OR optimization opportunity
  - The optimizer has more freedom to reorder tables in the FROM clause even in there are LEFT joins.
- Extension loading supported added to WinCE
- Allow constraint names on the DEFAULT clause in a table definition
- Added the ".bail" command to the command-line shell
- Make CSV (comma separate value) output from the command-line shell more closely aligned to accepted practice
- Experimental FTS2 module added
- Use sqlite3_mprintf() instead of strdup() to avoid libc dependencies
- VACUUM uses a temporary file in the official TEMP folder, not in the same directory as the original database
- The prefix on temporary filenames on Windows is changed from "sqlite" to "etilqs".

### 2006-10-09 (3.3.8)

- Support for full text search using the FTS1 module (beta)
- Added Mac OS X locking patches (beta - disabled by default)
- Introduce extended error codes and add error codes for various kinds of I/O errors.
- Added support for IF EXISTS on CREATE/DROP TRIGGER/VIEW
- Fix the regression test suite so that it works with Tcl8.5
- Enhance sqlite3_set_authorizer() to provide notification of calls to SQL functions.
- Added experimental API: sqlite3_auto_extension()
- Various minor bug fixes

### 2006-08-12 (3.3.7)

- Added support for virtual tables (beta)
- Added support for dynamically loaded extensions (beta)
- The sqlite3_interrupt() routine can be called for a different thread
- Added the MATCH operator.
- The default file format is now 1.

### 2006-06-06 (3.3.6)

- Plays better with virus scanners on Windows
- Faster :memory: databases
- Fix an obscure segfault in UTF-8 to UTF-16 conversions
- Added driver for OS/2
- Correct column meta-information returned for aggregate queries
- Enhanced output from EXPLAIN QUERY PLAN
- LIMIT 0 now works on subqueries
- Bug fixes and performance enhancements in the query optimizer
- Correctly handle NULL filenames in ATTACH and DETACH
- Improved syntax error messages in the parser
- Fix type coercion rules for the IN operator

### 2006-04-05 (3.3.5)

- CHECK constraints use conflict resolution algorithms correctly.
- The SUM() function throws an error on integer overflow.
- Choose the column names in a compound query from the left-most SELECT instead of the right-most.
- The sqlite3_create_collation() function honors the SQLITE_UTF16_ALIGNED flag.
- SQLITE_SECURE_DELETE compile-time option causes deletes to overwrite old data with zeros.
- Detect integer overflow in abs().
- The random() function provides 64 bits of randomness instead of only 32 bits.
- Parser detects and reports automaton stack overflow.
- Change the round() function to return REAL instead of TEXT.
- Allow WHERE clause terms on the left table of a LEFT OUTER JOIN to contain aggregate subqueries.
- Skip over leading spaces in text to numeric conversions.
- Various minor bug and documentation typo fixes and performance enhancements.

### 2006-02-11 (3.3.4)

- Fix a blunder in the Unix mutex implementation that can lead to deadlock on multithreaded systems.
- Fix an alignment problem on 64-bit machines
- Added the fullfsync pragma.
- Fix an optimizer bug that could have caused some unusual LEFT OUTER JOINs to give incorrect results.
- The SUM function detects integer overflow and converts to accumulating an approximate result using floating point numbers
- Host parameter names can begin with '@' for compatibility with SQL Server.
- Other miscellaneous bug fixes

### 2006-01-31 (3.3.3)

- Removed support for an ON CONFLICT clause on CREATE INDEX - it never worked correctly so this should not present any backward compatibility problems.
- Authorizer callback now notified of ALTER TABLE ADD COLUMN commands
- After any changes to the TEMP database schema, all prepared statements are invalidated and must be recreated using a new call to sqlite3_prepare()
- Other minor bug fixes in preparation for the first stable release of version 3.3

### 2006-01-24 (3.3.2 beta)

- Bug fixes and speed improvements. Improved test coverage.
- Changes to the OS-layer interface: mutexes must now be recursive.
- Discontinue the use of thread-specific data for out-of-memory exception handling

### 2006-01-16 (3.3.1 alpha)

- Countless bug fixes
- Speed improvements
- Database connections can now be used by multiple threads, not just the thread in which they were created.

### 2006-01-11 (3.3.0 alpha)

- CHECK constraints
- IF EXISTS and IF NOT EXISTS clauses on CREATE/DROP TABLE/INDEX.
- DESC indices
- More efficient encoding of boolean values resulting in smaller database files
- More aggressive SQLITE_OMIT_FLOATING_POINT
- Separate INTEGER and REAL affinity
- Added a virtual function layer for the OS interface
- "exists" method added to the TCL interface
- Improved response to out-of-memory errors
- Database cache can be optionally shared between connections in the same thread
- Optional READ UNCOMMITTED isolation (instead of the default isolation level of SERIALIZABLE) and table level locking when database connections share a common cache.

### 2005-12-19 (3.2.8)

- Fix an obscure bug that can cause database corruption under the following unusual circumstances: A large INSERT or UPDATE statement which is part of an even larger transaction fails due to a uniqueness constraint but the containing transaction commits.

### 2005-12-19 (2.8.17)

- Fix an obscure bug that can cause database corruption under the following unusual circumstances: A large INSERT or UPDATE statement which is part of an even larger transaction fails due to a uniqueness contraint but the containing transaction commits.

### 2005-09-24 (3.2.7)

- GROUP BY now considers NULLs to be equal again, as it should
- Now compiles on Solaris and OpenBSD and other Unix variants that lack the fdatasync() function
- Now compiles on MSVC++6 again
- Fix uninitialized variables causing malfunctions for various obscure queries
- Correctly compute a LEFT OUTER JOINs that is constrained on the left table only

### 2005-09-17 (3.2.6)

- Fix a bug that can cause database corruption if a VACUUM (or autovacuum) fails and is rolled back on a database that is larger than 1GiB
- LIKE optimization now works for columns with COLLATE NOCASE
- ORDER BY and GROUP BY now use bounded memory
- Added support for COUNT(DISTINCT expr)
- Change the way SUM() handles NULL values in order to comply with the SQL standard
- Use fdatasync() instead of fsync() where possible in order to speed up commits slightly
- Use of the CROSS keyword in a join turns off the table reordering optimization
- Added the experimental and undocumented EXPLAIN QUERY PLAN capability
- Use the unicode API in Windows

### 2005-08-27 (3.2.5)

- Fix a bug effecting DELETE and UPDATE statements that changed more than 40960 rows.
- Change the makefile so that it no longer requires GNUmake extensions
- Fix the --enable-threadsafe option on the configure script
- Fix a code generator bug that occurs when the left-hand side of an IN operator is constant and the right-hand side is a SELECT statement
- The PRAGMA synchronous=off statement now disables syncing of the master journal file in addition to the normal rollback journals

### 2005-08-24 (3.2.4)

- Fix a bug introduced in the previous release that can cause a segfault while generating code for complex WHERE clauses.
- Allow floating point literals to begin or end with a decimal point.

### 2005-08-21 (3.2.3)

- Added support for the CAST operator
- Tcl interface allows BLOB values to be transferred to user-defined functions
- Added the "transaction" method to the Tcl interface
- Allow the DEFAULT value of a column to call functions that have constant operands
- Added the ANALYZE command for gathering statistics on indices and using those statistics when picking an index in the optimizer
- Remove the limit (formerly 100) on the number of terms in the WHERE clause
- The right-hand side of the IN operator can now be a list of expressions instead of just a list of constants
- Rework the optimizer so that it is able to make better use of indices
- The order of tables in a join is adjusted automatically to make better use of indices
- The IN operator is now a candidate for optimization even if the left-hand side is not the left-most term of the index. Multiple IN operators can be used with the same index.
- WHERE clause expressions using BETWEEN and OR are now candidates for optimization
- Added the "case_sensitive_like" pragma and the SQLITE_CASE_SENSITIVE_LIKE compile-time option to set its default value to "on".
- Use indices to help with GLOB expressions and LIKE expressions too when the case_sensitive_like pragma is enabled
- Added support for grave-accent quoting for compatibility with MySQL
- Improved test coverage
- Dozens of minor bug fixes

### 2005-06-12 (3.2.2)

- Added the sqlite3_db_handle() API
- Added the sqlite3_get_autocommit() API
- Added a REGEXP operator to the parser. There is no function to back up this operator in the standard build but users can add their own using sqlite3_create_function()
- Speed improvements and library footprint reductions.
- Fix byte alignment problems on 64-bit architectures.
- Many, many minor bug fixes and documentation updates.

### 2005-03-29 (3.2.1)

- Fix a memory allocation error in the new ADD COLUMN comment.
- Documentation updates

### 2005-03-21 (3.2.0)

- Added support for ALTER TABLE ADD COLUMN.
- Added support for the "T" separator in ISO-8601 date/time strings.
- Improved support for Cygwin.
- Numerous bug fixes and documentation updates.

### 2005-03-17 (3.1.6)

- Fix a bug that could cause database corruption when inserting record into tables with around 125 columns.
- sqlite3_step() is now much more likely to invoke the busy handler and less likely to return SQLITE_BUSY.
- Fix memory leaks that used to occur after a malloc() failure.

### 2005-03-11 (3.1.5)

- The ioctl on Mac OS X to control syncing to disk is F_FULLFSYNC, not F_FULLSYNC. The previous release had it wrong.

### 2005-03-11 (3.1.4)

- Fix a bug in autovacuum that could cause database corruption if a CREATE UNIQUE INDEX fails because of a constraint violation. This problem only occurs if the new autovacuum feature introduced in version 3.1 is turned on.
- The F_FULLSYNC ioctl (currently only supported on Mac OS X) is disabled if the synchronous pragma is set to something other than "full".
- Add additional forward compatibility to the future version 3.2 database file format.
- Fix a bug in WHERE clauses of the form (rowid<'2')
- New SQLITE_OMIT_... compile-time options added
- Updates to the man page
- Remove the use of strcasecmp() from the shell
- Windows DLL exports symbols Tclsqlite_Init and Sqlite_Init

### 2005-02-19 (3.1.3)

- Fix a problem with VACUUM on databases from which tables containing AUTOINCREMENT have been dropped.
- Add forward compatibility to the future version 3.2 database file format.
- Documentation updates

### 2005-02-15 (3.1.2)

- Fix a bug that can lead to database corruption if there are two open connections to the same database and one connection does a VACUUM and the second makes some change to the database.
- Allow "?" parameters in the LIMIT clause.
- Fix VACUUM so that it works with AUTOINCREMENT.
- Fix a race condition in AUTOVACUUM that can lead to corrupt databases
- Add a numeric version number to the sqlite3.h include file.
- Other minor bug fixes and performance enhancements.

### 2005-02-15 (2.8.16)

- Fix a bug that can lead to database corruption if there are two open connections to the same database and one connection does a VACUUM and the second makes some change to the database.
- Correctly handle quoted names in CREATE INDEX statements.
- Fix a naming conflict between sqlite.h and sqlite3.h.
- Avoid excess heap usage when copying expressions.
- Other minor bug fixes.

### 2005-02-01 (3.1.1 BETA)

- Automatic caching of prepared statements in the TCL interface
- ATTACH and DETACH as well as some other operations cause existing prepared statements to expire.
- Numerous minor bug fixes

### 2005-01-21 (3.1.0 ALPHA)

- Autovacuum support added
- CURRENT_TIME, CURRENT_DATE, and CURRENT_TIMESTAMP added
- Support for the EXISTS clause added.
- Support for correlated subqueries added.
- Added the ESCAPE clause on the LIKE operator.
- Support for ALTER TABLE ... RENAME TABLE ... added
- AUTOINCREMENT keyword supported on INTEGER PRIMARY KEY
- Many SQLITE_OMIT_ macros inserts to omit features at compile-time and reduce the library footprint.
- The REINDEX command was added.
- The engine no longer consults the main table if it can get all the information it needs from an index.
- Many nuisance bugs fixed.

### 2004-10-12 (3.0.8)

- Add support for DEFERRED, IMMEDIATE, and EXCLUSIVE transactions.
- Allow new user-defined functions to be created when there are already one or more precompiled SQL statements.
- Fix portability problems for MinGW/MSYS.
- Fix a byte alignment problem on 64-bit Sparc machines.
- Fix the ".import" command of the shell so that it ignores \r characters at the end of lines.
- The "csv" mode option in the shell puts strings inside double-quotes.
- Fix typos in documentation.
- Convert array constants in the code to have type "const".
- Numerous code optimizations, specially optimizations designed to make the code footprint smaller.

### 2004-09-18 (3.0.7)

- The BTree module allocates large buffers using malloc() instead of off of the stack, in order to play better on machines with limited stack space.
- Fixed naming conflicts so that versions 2.8 and 3.0 can be linked and used together in the same ANSI-C source file.
- New interface: sqlite3_bind_parameter_index()
- Add support for wildcard parameters of the form: "?nnn"
- Fix problems found on 64-bit systems.
- Removed encode.c file (containing unused routines) from the version 3.0 source tree.
- The sqlite3_trace() callbacks occur before each statement is executed, not when the statement is compiled.
- Makefile updates and miscellaneous bug fixes.

### 2004-09-02 (3.0.6 beta)

- Better detection and handling of corrupt database files.
- The sqlite3_step() interface returns SQLITE_BUSY if it is unable to commit a change because of a lock
- Combine the implementations of LIKE and GLOB into a single pattern-matching subroutine.
- Miscellaneous code size optimizations and bug fixes

### 2004-08-29 (3.0.5 beta)

- Support for ":AAA" style bind parameter names.
- Added the new sqlite3_bind_parameter_name() interface.
- Support for TCL variable names embedded in SQL statements in the TCL bindings.
- The TCL bindings transfer data without necessarily doing a conversion to a string.
- The database for TEMP tables is not created until it is needed.
- Add the ability to specify an alternative temporary file directory using the "sqlite_temp_directory" global variable.
- A compile-time option (SQLITE_BUSY_RESERVED_LOCK) causes the busy handler to be called when there is contention for a RESERVED lock.
- Various bug fixes and optimizations

### 2004-08-09 (3.0.4 beta)

- CREATE TABLE and DROP TABLE now work correctly as prepared statements.
- Fix a bug in VACUUM and UNIQUE indices.
- Add the ".import" command to the command-line shell.
- Fix a bug that could cause index corruption when an attempt to delete rows of a table is blocked by a pending query.
- Library size optimizations.
- Other minor bug fixes.

### 2004-07-22 (2.8.15)

- This is a maintenance release only. Various minor bugs have been fixed and some portability enhancements are added.

### 2004-07-22 (3.0.3 beta)

- The second beta release for SQLite 3.0.
- Add support for "PRAGMA page_size" to adjust the page size of the database.
- Various bug fixes and documentation updates.

### 2004-06-30 (3.0.2 beta)

- The first beta release for SQLite 3.0.

### 2004-06-22 (3.0.1 alpha)

- *** Alpha Release - Research And Testing Use Only ***
- Lots of bug fixes.

### 2004-06-18 (3.0.0 alpha)

- *** Alpha Release - Research And Testing Use Only ***
- Support for internationalization including UTF-8, UTF-16, and user defined collating sequences.
- New file format that is 25% to 35% smaller for typical use.
- Improved concurrency.
- Atomic commits for ATTACHed databases.
- Remove cruft from the APIs.
- BLOB support.
- 64-bit rowids.
- More information.

### 2004-06-09 (2.8.14)

- Fix the min() and max() optimizer so that it works when the FROM clause consists of a subquery.
- Ignore extra whitespace at the end of of "." commands in the shell.
- Bundle sqlite_encode_binary() and sqlite_decode_binary() with the library.
- The TEMP_STORE and DEFAULT_TEMP_STORE pragmas now work.
- Code changes to compile cleanly using OpenWatcom.
- Fix VDBE stack overflow problems with INSTEAD OF triggers and NULLs in IN operators.
- Add the global variable sqlite_temp_directory which if set defines the directory in which temporary files are stored.
- sqlite_interrupt() plays well with VACUUM.
- Other minor bug fixes.

### 2004-03-08 (2.8.13)

- Refactor parts of the code in order to make the code footprint smaller. The code is now also a little bit faster.
- sqlite_exec() is now implemented as a wrapper around sqlite_compile() and sqlite_step().
- The built-in min() and max() functions now honor the difference between NUMERIC and TEXT datatypes. Formerly, min() and max() always assumed their arguments were of type NUMERIC.
- New HH:MM:SS modifier to the built-in date/time functions.
- Experimental sqlite_last_statement_changes() API added. Fixed the last_insert_rowid() function so that it works correctly with triggers.
- Add functions prototypes for the database encryption API.
- Fix several nuisance bugs.

### 2004-02-08 (2.8.12)

- Fix a bug that will might corrupt the rollback journal if a power failure or external program halt occurs in the middle of a COMMIT. The corrupt journal can lead to database corruption when it is rolled back.
- Reduce the size and increase the speed of various modules, especially the virtual machine.
- Allow "<expr> IN <table>" as a shorthand for "<expr> IN (SELECT * FROM <table>".
- Optimizations to the sqlite_mprintf() routine.
- Make sure the MIN() and MAX() optimizations work within subqueries.

### 2004-01-14 (2.8.11)

- Fix a bug in how the IN operator handles NULLs in subqueries. The bug was introduced by the previous release.

### 2004-01-14 (2.8.10)

- Fix a potential database corruption problem on Unix caused by the fact that all POSIX advisory locks are cleared whenever you close() a file. The work around it to embargo all close() calls while locks are outstanding.
- Performance enhancements on some corner cases of COUNT(*).
- Make sure the in-memory backend response sanely if malloc() fails.
- Allow sqlite_exec() to be called from within user-defined SQL functions.
- Improved accuracy of floating-point conversions using "long double".
- Bug fixes in the experimental date/time functions.

### 2004-01-06 (2.8.9)

- Fix a 32-bit integer overflow problem that could result in corrupt indices in a database if large negative numbers (less than -2147483648) were inserted into an indexed numeric column.
- Fix a locking problem on multi-threaded Linux implementations.
- Always use "." instead of "," as the decimal point even if the locale requests ",".
- Added UTC to localtime conversions to the experimental date/time functions.
- Bug fixes to date/time functions.

### 2003-12-18 (2.8.8)

- Fix a critical bug introduced into 2.8.0 which could cause database corruption.
- Fix a problem with 3-way joins that do not use indices
- The VACUUM command now works with the non-callback API
- Improvements to the "PRAGMA integrity_check" command

### 2003-12-04 (2.8.7)

- Added experimental sqlite_bind() and sqlite_reset() APIs.
- If the name of the database is an empty string, open a new database in a temporary file that is automatically deleted when the database is closed.
- Performance enhancements in the lemon-generated parser
- Experimental date/time functions revised.
- Disallow temporary indices on permanent tables.
- Documentation updates and typo fixes
- Added experimental sqlite_progress_handler() callback API
- Removed support for the Oracle8 outer join syntax.
- Allow GLOB and LIKE operators to work as functions.
- Other minor documentation and makefile changes and bug fixes.

### 2003-08-22 (2.8.6)

- Moved the CVS repository to www.sqlite.org
- Update the NULL-handling documentation.
- Experimental date/time functions added.
- Bug fix: correctly evaluate a view of a view without segfaulting.
- Bug fix: prevent database corruption if you dropped a trigger that had the same name as a table.
- Bug fix: allow a VACUUM (without segfaulting) on an empty database after setting the EMPTY_RESULT_CALLBACKS pragma.
- Bug fix: if an integer value will not fit in a 32-bit int, store it in a double instead.
- Bug fix: Make sure the journal file directory entry is committed to disk before writing the database file.

### 2003-07-22 (2.8.5)

- Make LIMIT work on a compound SELECT statement.
- LIMIT 0 now shows no rows. Use LIMIT -1 to see all rows.
- Correctly handle comparisons between an INTEGER PRIMARY KEY and a floating point number.
- Fix several important bugs in the new ATTACH and DETACH commands.
- Updated the NULL-handling document.
- Allow NULL arguments in sqlite_compile() and sqlite_step().
- Many minor bug fixes

### 2003-06-29 (2.8.4)

- Enhanced the "PRAGMA integrity_check" command to verify indices.
- Added authorization hooks for the new ATTACH and DETACH commands.
- Many documentation updates
- Many minor bug fixes

### 2003-06-04 (2.8.3)

- Fix a problem that will corrupt the indices on a table if you do an INSERT OR REPLACE or an UPDATE OR REPLACE on a table that contains an INTEGER PRIMARY KEY plus one or more indices.
- Fix a bug in Windows locking code so that locks work correctly when simultaneously accessed by Win95 and WinNT systems.
- Add the ability for INSERT and UPDATE statements to refer to the "rowid" (or "_rowid_" or "oid") columns.
- Other important bug fixes

### 2003-05-17 (2.8.2)

- Fix a problem that will corrupt the database file if you drop a table from the main database that has a TEMP index.

### 2003-05-17 (2.8.1)

- Reactivated the VACUUM command that reclaims unused disk space in a database file.
- Added the ATTACH and DETACH commands to allow interacting with multiple database files at the same time.
- Added support for TEMP triggers and indices.
- Added support for in-memory databases.
- Removed the experimental sqlite_open_aux_file(). Its function is subsumed in the new ATTACH command.
- The precedence order for ON CONFLICT clauses was changed so that ON CONFLICT clauses on BEGIN statements have a higher precedence than ON CONFLICT clauses on constraints.
- Many, many bug fixes and compatibility enhancements.

### 2003-02-16 (2.8.0)

- Modified the journal file format to make it more resistant to corruption that can occur after an OS crash or power failure.
- Added a new C/C++ API that does not use callback for returning data.

### 2003-01-25 (2.7.6)

- Performance improvements. The library is now much faster.
- Added the sqlite_set_authorizer() API. Formal documentation has not been written - see the source code comments for instructions on how to use this function.
- Fix a bug in the GLOB operator that was preventing it from working with upper-case letters.
- Various minor bug fixes.

### 2002-12-28 (2.7.5)

- Fix an uninitialized variable in pager.c which could (with a probability of about 1 in 4 billion) result in a corrupted database.

### 2002-12-17 (2.7.4)

- Database files can now grow to be up to 2^41 bytes. The old limit was 2^31 bytes.
- The optimizer will now scan tables in the reverse if doing so will satisfy an ORDER BY ... DESC clause.
- The full pathname of the database file is now remembered even if a relative path is passed into sqlite_open(). This allows the library to continue operating correctly after a chdir().
- Speed improvements in the VDBE.
- Lots of little bug fixes.

### 2002-10-31 (2.7.3)

- Various compiler compatibility fixes.
- Fix a bug in the "expr IN ()" operator.
- Accept column names in parentheses.
- Fix a problem with string memory management in the VDBE
- Fix a bug in the "table_info" pragma"
- Export the sqlite_function_type() API function in the Windows DLL
- Fix locking behavior under Windows
- Fix a bug in LEFT OUTER JOIN

### 2002-09-25 (2.7.2)

- Prevent journal file overflows on huge transactions.
- Fix a memory leak that occurred when sqlite_open() failed.
- Honor the ORDER BY and LIMIT clause of a SELECT even if the result set is used for an INSERT.
- Do not put write locks on the file used to hold TEMP tables.
- Added documentation on SELECT DISTINCT and on how SQLite handles NULLs.
- Fix a problem that was causing poor performance when many thousands of SQL statements were executed by a single sqlite_exec() call.

### 2002-08-31 (2.7.1)

- Fix a bug in the ORDER BY logic that was introduced in version 2.7.0
- C-style comments are now accepted by the tokenizer.
- INSERT runs a little faster when the source is a SELECT statement.

### 2002-08-25 (2.7.0)

- Make a distinction between numeric and text values when sorting. Text values sort according to memcmp(). Numeric values sort in numeric order.
- Allow multiple simultaneous readers under Windows by simulating the reader/writers locks that are missing from Win95/98/ME.
- An error is now returned when trying to start a transaction if another transaction is already active.

### 2002-08-13 (2.6.3)

- Add the ability to read both little-endian and big-endian databases. So a database created under SunOS or Mac OS X can be read and written under Linux or Windows and vice versa.
- Convert to the new website: http://www.sqlite.org/
- Allow transactions to span Linux Threads
- Bug fix in the processing of the ORDER BY clause for GROUP BY queries

### 2002-07-31 (2.6.2)

- Text files read by the COPY command can now have line terminators of LF, CRLF, or CR.
- SQLITE_BUSY is handled correctly if encountered during database initialization.
- Fix to UPDATE triggers on TEMP tables.
- Documentation updates.

### 2002-07-19 (2.6.1)

- Include a static string in the library that responds to the RCS "ident" command and which contains the library version number.
- Fix an assertion failure that occurred when deleting all rows of a table with the "count_changes" pragma turned on.
- Better error reporting when problems occur during the automatic 2.5.6 to 2.6.0 database format upgrade.

### 2002-07-18 (2.6.0)

- Change the format of indices to correct a design flaw the originated with version 2.1.0. *** This is an incompatible file format change *** When version 2.6.0 or later of the library attempts to open a database file created by version 2.5.6 or earlier, it will automatically and irreversibly convert the file format. Make backup copies of older database files before opening them with version 2.6.0 of the library.

### 2002-07-07 (2.5.6)

- Fix more problems with rollback. Enhance the test suite to exercise the rollback logic extensively in order to prevent any future problems.

### 2002-07-06 (2.5.5)

- Fix a bug which could cause database corruption during a rollback. This bugs was introduced in version 2.4.0 by the freelist optimization of checkin [410].
- Fix a bug in aggregate functions for VIEWs.
- Other minor changes and enhancements.

### 2002-07-01 (2.5.4)

- Make the "AS" keyword optional again.
- The datatype of columns now appear in the 4th argument to the callback.
- Added the sqlite_open_aux_file() API, though it is still mostly undocumented and untested.
- Added additional test cases and fixed a few bugs that those test cases found.

### 2002-06-25 (2.5.3)

- Bug fix: Database corruption can occur due to the optimization that was introduced in version 2.4.0 (check-in [410]). The problem should now be fixed. The use of versions 2.4.0 through 2.5.2 is not recommended.

### 2002-06-25 (2.5.2)

- Added the new SQLITE_TEMP_MASTER table which records the schema for temporary tables in the same way that SQLITE_MASTER does for persistent tables.
- Added an optimization to UNION ALL
- Fixed a bug in the processing of LEFT OUTER JOIN
- The LIMIT clause now works on subselects
- ORDER BY works on subselects
- There is a new TypeOf() function used to determine if an expression is numeric or text.
- Autoincrement now works for INSERT from a SELECT.

### 2002-06-19 (2.5.1)

- The query optimizer now attempts to implement the ORDER BY clause using an index. Sorting is still used if not suitable index is available.

### 2002-06-17 (2.5.0)

- Added support for row triggers.
- Added SQL-92 compliant handling of NULLs.
- Add support for the full SQL-92 join syntax and LEFT OUTER JOINs.
- Double-quoted strings interpreted as column names not text literals.
- Parse (but do not implement) foreign keys.
- Performance improvements in the parser, pager, and WHERE clause code generator.
- Make the LIMIT clause work on subqueries. (ORDER BY still does not work, though.)
- Added the "%Q" expansion to sqlite_*_printf().
- Bug fixes too numerous to mention (see the change log).

### 2002-05-10 (2.4.12)

- Added logic to detect when the library API routines are called out of sequence.

### 2002-05-08 (2.4.11)

- Bug fix: Column names in the result set were not being generated correctly for some (rather complex) VIEWs. This could cause a segfault under certain circumstances.

### 2002-05-03 (2.4.10)

- Bug fix: Generate correct column headers when a compound SELECT is used as a subquery.
- Added the sqlite_encode_binary() and sqlite_decode_binary() functions to the source tree. But they are not yet linked into the library.
- Documentation updates.
- Export the sqlite_changes() function from Windows DLLs.
- Bug fix: Do not attempt the subquery flattening optimization on queries that lack a FROM clause. To do so causes a segfault.

### 2002-04-22 (2.4.9)

- Fix a bug that was causing the precompiled binary of SQLITE.EXE to report "out of memory" under Windows 98.

### 2002-04-20 (2.4.8)

- Make sure VIEWs are created after their corresponding TABLEs in the output of the .dump command in the shell.
- Speed improvements: Do not do synchronous updates on TEMP tables.
- Many improvements and enhancements to the shell.
- Make the GLOB and LIKE operators functions that can be overridden by a programmer. This allows, for example, the LIKE operator to be changed to be case sensitive.

### 2002-04-12 (2.4.7)

- Add the ability to put TABLE.* in the column list of a SELECT statement.
- Permit SELECT statements without a FROM clause.
- Added the last_insert_rowid() SQL function.
- Do not count rows where the IGNORE conflict resolution occurs in the row count.
- Make sure functions expressions in the VALUES clause of an INSERT are correct.
- Added the sqlite_changes() API function to return the number of row that changed in the most recent operation.

### 2002-04-02 (2.4.6)

- Bug fix: Correctly handle terms in the WHERE clause of a join that do not contain a comparison operator.

### 2002-04-02 (2.4.5)

- Bug fix: Correctly handle functions that appear in the WHERE clause of a join.
- When the PRAGMA vdbe_trace=ON is set, correctly print the P3 operand value when it is a pointer to a structure rather than a pointer to a string.
- When inserting an explicit NULL into an INTEGER PRIMARY KEY, convert the NULL value into a unique key automatically.

### 2002-03-30 (2.4.4)

- Allow "VIEW" to be a column name
- Added support for CASE expressions (patch from Dan Kennedy)
- Added RPMS to the delivery (patches from Doug Henry)
- Fix typos in the documentation
- Cut over configuration management to a new CVS repository with its own CVSTrac bug tracking system.

### 2002-03-23 (2.4.3)

- Fix a bug in SELECT that occurs when a compound SELECT is used as a subquery in the FROM of a SELECT.
- The sqlite_get_table() function now returns an error if you give it two or more SELECTs that return different numbers of columns.

### 2002-03-20 (2.4.2)

- Bug fix: Fix an assertion failure that occurred when ROWID was a column in a SELECT statement on a view.
- Bug fix: Fix an uninitialized variable in the VDBE that would could an assert failure.
- Make the os.h header file more robust in detecting when the compile is for Windows and when it is for Unix.

### 2002-03-13 (2.4.1)

- Using an unnamed subquery in a FROM clause would cause a segfault.
- The parser now insists on seeing a semicolon or the end of input before executing a statement. This avoids an accidental disaster if the WHERE keyword is misspelled in an UPDATE or DELETE statement.

### 2002-03-11 (2.4.0)

- Change the name of the sanity_check PRAGMA to integrity_check and make it available in all compiles.
- SELECT min() or max() of an indexed column with no WHERE or GROUP BY clause is handled as a special case which avoids a complete table scan.
- Automatically generated ROWIDs are now sequential.
- Do not allow dot-commands of the command-line shell to occur in the middle of a real SQL command.
- Modifications to the "lemon" parser generator so that the parser tables are 4 times smaller.
- Added support for user-defined functions implemented in C.
- Added support for new functions: coalesce(), lower(), upper(), and random()
- Added support for VIEWs.
- Added the subquery flattening optimizer.
- Modified the B-Tree and Pager modules so that disk pages that do not contain real data (free pages) are not journaled and are not written from memory back to the disk when they change. This does not impact database integrity, since the pages contain no real data, but it does make large INSERT operations about 2.5 times faster and large DELETEs about 5 times faster.
- Made the CACHE_SIZE pragma persistent
- Added the SYNCHRONOUS pragma
- Fixed a bug that was causing updates to fail inside of transactions when the database contained a temporary table.

### 2002-02-19 (2.3.3)

- Allow identifiers to be quoted in square brackets, for compatibility with MS-Access.
- Added support for sub-queries in the FROM clause of a SELECT.
- More efficient implementation of sqliteFileExists() under Windows. (by Joel Luscy)
- The VALUES clause of an INSERT can now contain expressions, including scalar SELECT clauses.
- Added support for CREATE TABLE AS SELECT
- Bug fix: Creating and dropping a table all within a single transaction was not working.

### 2002-02-14 (2.3.2)

- Bug fix: There was an incorrect assert() in pager.c. The real code was all correct (as far as is known) so everything should work OK if you compile with -DNDEBUG=1. When asserts are not disabled, there could be a fault.

### 2002-02-13 (2.3.1)

- Bug fix: An assertion was failing if "PRAGMA full_column_names=ON;" was set and you did a query that used a rowid, like this: "SELECT rowid, * FROM ...".

### 2002-02-03 (2.3.0)

- Fix a serious bug in the INSERT command which was causing data to go into the wrong columns if the data source was a SELECT and the INSERT clauses specified its columns in some order other than the default.
- Added the ability to resolve constraint conflicts is ways other than an abort and rollback. See the documentation on the "ON CONFLICT" clause for details.
- Temporary files are now automatically deleted by the operating system when closed. There are no more dangling temporary files on a program crash. (If the OS crashes, fsck will delete the file after reboot under Unix. I do not know what happens under Windows.)
- NOT NULL constraints are honored.
- The COPY command puts NULLs in columns whose data is '\N'.
- In the COPY command, backslash can now be used to escape a newline.
- Added the SANITY_CHECK pragma.

### 2002-01-28 (2.2.5)

- Important bug fix: the IN operator was not working if either the left-hand or right-hand side was derived from an INTEGER PRIMARY KEY.
- Do not escape the backslash '\' character in the output of the sqlite command-line access program.

### 2002-01-22 (2.2.4)

- The label to the right of an AS in the column list of a SELECT can now be used as part of an expression in the WHERE, ORDER BY, GROUP BY, and/or HAVING clauses.
- Fix a bug in the -separator command-line option to the sqlite command.
- Fix a problem with the sort order when comparing upper-case strings against characters greater than 'Z' but less than 'a'.
- Report an error if an ORDER BY or GROUP BY expression is constant.

### 2002-01-16 (2.2.3)

- Fix warning messages in VC++ 7.0. (Patches from nicolas352001)
- Make the library thread-safe. (The code is there and appears to work but has not been stressed.)
- Added the new sqlite_last_insert_rowid() API function.

### 2002-01-14 (2.2.2)

- Bug fix: An assertion was failing when a temporary table with an index had the same name as a permanent table created by a separate process.
- Bug fix: Updates to tables containing an INTEGER PRIMARY KEY and an index could fail.

### 2002-01-09 (2.2.1)

- Bug fix: An attempt to delete a single row of a table with a WHERE clause of "ROWID=x" when no such rowid exists was causing an error.
- Bug fix: Passing in a NULL as the 3rd parameter to sqlite_open() would sometimes cause a coredump.
- Bug fix: DROP TABLE followed by a CREATE TABLE with the same name all within a single transaction was causing a coredump.
- Makefile updates from A. Rottmann

### 2001-12-22 (2.2.0)

- Columns of type INTEGER PRIMARY KEY are actually used as the primary key in underlying B-Tree representation of the table.
- Several obscure, unrelated bugs were found and fixed while implemented the integer primary key change of the previous bullet.
- Added the ability to specify "*" as part of a larger column list in the result section of a SELECT statement. For example: "SELECT rowid, * FROM table1;".
- Updates to comments and documentation.

### 2001-12-15 (2.1.7)

- Fix a bug in CREATE TEMPORARY TABLE which was causing the table to be initially allocated in the main database file instead of in the separate temporary file. This bug could cause the library to suffer an assertion failure and it could cause "page leaks" in the main database file.
- Fix a bug in the b-tree subsystem that could sometimes cause the first row of a table to be repeated during a database scan.

### 2001-12-14 (2.1.6)

- Fix the locking mechanism yet again to prevent sqlite_exec() from returning SQLITE_PROTOCOL unnecessarily. This time the bug was a race condition in the locking code. This change affects both POSIX and Windows users.

### 2001-12-06 (2.1.5)

- Fix for another problem (unrelated to the one fixed in 2.1.4) that sometimes causes sqlite_exec() to return SQLITE_PROTOCOL unnecessarily. This time the bug was in the POSIX locking code and should not effect Windows users.

### 2001-12-05 (2.1.4)

- Sometimes sqlite_exec() would return SQLITE_PROTOCOL when it should have returned SQLITE_BUSY.
- The fix to the previous bug uncovered a deadlock which was also fixed.
- Add the ability to put a single .command in the second argument of the sqlite shell
- Updates to the FAQ

### 2001-11-24 (2.1.3)

- Fix the behavior of comparison operators (ex: "<", "==", etc.) so that they are consistent with the order of entries in an index.
- Correct handling of integers in SQL expressions that are larger than what can be represented by the machine integer.

### 2001-11-23 (2.1.2)

- Changes to support 64-bit architectures.
- Fix a bug in the locking protocol.
- Fix a bug that could (rarely) cause the database to become unreadable after a DROP TABLE due to corruption to the SQLITE_MASTER table.
- Change the code so that version 2.1.1 databases that were rendered unreadable by the above bug can be read by this version of the library even though the SQLITE_MASTER table is (slightly) corrupted.

### 2001-11-13 (2.1.1)

- Bug fix: Sometimes arbitrary strings were passed to the callback function when the actual value of a column was NULL.

### 2001-11-12 (2.1.0)

- Change the format of data records so that records up to 16MB in size can be stored.
- Change the format of indices to allow for better query optimization.
- Implement the "LIMIT ... OFFSET ..." clause on SELECT statements.

### 2001-11-03 (2.0.8)

- Made selected parameters in API functions const. This should be fully backwards compatible.
- Documentation updates
- Simplify the design of the VDBE by restricting the number of sorters and lists to 1. In practice, no more than one sorter and one list was ever used anyhow.

### 2001-10-22 (2.0.7)

- Any UTF-8 character or ISO8859 character can be used as part of an identifier.
- Patches from Christian Werner to improve ODBC compatibility and to fix a bug in the round() function.
- Plug some memory leaks that use to occur if malloc() failed. We have been and continue to be memory leak free as long as malloc() works.
- Changes to some test scripts so that they work on Windows in addition to Unix.

### 2001-10-19 (2.0.6)

- Added the EMPTY_RESULT_CALLBACKS pragma
- Support for UTF-8 and ISO8859 characters in column and table names.
- Bug fix: Compute correct table names with the FULL_COLUMN_NAMES pragma is turned on.

### 2001-10-15 (2.0.5)

- Added the COUNT_CHANGES pragma.
- Changes to the FULL_COLUMN_NAMES pragma to help out the ODBC driver.
- Bug fix: "SELECT count(*)" was returning NULL for empty tables. Now it returns 0.

### 2001-10-13 (2.0.4)

- Bug fix: an obscure and relatively harmless bug was causing one of the tests to fail when gcc optimizations are turned on. This release fixes the problem.

### 2001-10-13 (2.0.3)

- Bug fix: the sqlite_busy_timeout() function was delaying 1000 times too long before failing.
- Bug fix: an assertion was failing if the disk holding the database file became full or stopped accepting writes for some other reason. New tests were added to detect similar problems in the future.
- Added new operators: & (bitwise-and) | (bitwise-or), ~ (ones-complement), << (shift left), >> (shift right).
- Added new functions: round() and abs().

### 2001-10-09 (2.0.2)

- Fix two bugs in the locking protocol. (One was masking the other.)
- Removed some unused "#include " that were causing problems for VC++.
- Fixed sqlite.h so that it is usable from C++
- Added the FULL_COLUMN_NAMES pragma. When set to "ON", the names of columns are reported back as TABLE.COLUMN instead of just COLUMN.
- Added the TABLE_INFO() and INDEX_INFO() pragmas to help support the ODBC interface.
- Added support for TEMPORARY tables and indices.

### 2001-10-02 (2.0.1)

- Remove some C++ style comments from btree.c so that it will compile using compilers other than gcc.
- The ".dump" output from the shell does not work if there are embedded newlines anywhere in the data. This is an old bug that was carried forward from version 1.0. To fix it, the ".dump" output no longer uses the COPY command. It instead generates INSERT statements.
- Extend the expression syntax to support "expr NOT NULL" (with a space between the "NOT" and the "NULL") in addition to "expr NOTNULL" (with no space).

### 200-09-28 (2.0.0)

- Automatically build binaries for Linux and Windows and put them on the website.

### 2001-09-28 (2.0-alpha-4)

- Incorporate makefile patches form A. Rottmann to use LIBTOOL

### 2001-09-27 (2.0-alpha-3)

- SQLite now honors the UNIQUE keyword in CREATE UNIQUE INDEX. Primary keys are required to be unique.
- File format changed back to what it was for alpha-1
- Fixes to the rollback and locking behavior

### 2001-09-20 (2.0-alpha-2)

- Initial release of version 2.0. The idea of renaming the library to "SQLus" was abandoned in favor of keeping the "SQLite" name and bumping the major version number.
- The pager and btree subsystems added back. They are now the only available backend.
- The Dbbe abstraction and the GDBM and memory drivers were removed.
- Copyright on all code was disclaimed. The library is now in the public domain.

### 2001-07-23 (1.0.32)

- Pager and btree subsystems removed. These will be used in a follow-on SQL server library named "SQLus".
- Add the ability to use quoted strings as table and column names in expressions.

### 2001-04-15 (1.0.31)

- Pager subsystem added but not yet used.
- More robust handling of out-of-memory errors.
- New tests added to the test suite.

### 2001-04-06 (1.0.30)

- Remove the sqlite_encoding TCL variable that was introduced in the previous version.
- Add options -encoding and -tcl-uses-utf to the sqlite TCL command.
- Add tests to make sure that tclsqlite was compiled using Tcl header files and libraries that match.

### 2001-04-05 (1.0.29)

- The library now assumes data is stored as UTF-8 if the --enable-utf8 option is given to configure. The default behavior is to assume iso8859-x, as it has always done. This only makes a difference for LIKE and GLOB operators and the LENGTH and SUBSTR functions.
- If the library is not configured for UTF-8 and the Tcl library is one of the newer ones that uses UTF-8 internally, then a conversion from UTF-8 to iso8859 and back again is done inside the TCL interface.

### 2001-04-04 (1.0.28)

- Added limited support for transactions. At this point, transactions will do table locking on the GDBM backend. There is no support (yet) for rollback or atomic commit.
- Added special column names ROWID, OID, and _ROWID_ that refer to the unique random integer key associated with every row of every table.
- Additional tests added to the regression suite to cover the new ROWID feature and the TCL interface bugs mentioned below.
- Changes to the "lemon" parser generator to help it work better when compiled using MSVC.
- Bug fixes in the TCL interface identified by Oleg Oleinick.

### 2001-03-20 (1.0.27)

- When doing DELETE and UPDATE, the library used to write the record numbers of records to be deleted or updated into a temporary file. This is changed so that the record numbers are held in memory.
- The DELETE command without a WHILE clause just removes the database files from the disk, rather than going through and deleting record by record.

### 2001-03-20 (1.0.26)

- A serious bug fixed on Windows. Windows users should upgrade. No impact to Unix.

### 2001-03-15 (1.0.25)

- Modify the test scripts to identify tests that depend on system load and processor speed and to warn the user that a failure of one of those (rare) tests does not necessarily mean the library is malfunctioning. No changes to code.

### 2001-03-14 (1.0.24)

- Fix a bug which was causing the UPDATE command to fail on systems where "malloc(0)" returns NULL. The problem does not appear on Windows, Linux, or HPUX but does cause the library to fail on QNX.

### 2001-02-20 (1.0.23)

- An unrelated (and minor) bug from Mark Muranwski fixed. The algorithm for figuring out where to put temporary files for a "memory:" database was not working quite right.

### 2001-02-19 (1.0.22)

- The previous fix was not quite right. This one seems to work better.

### 2001-02-19 (1.0.21)

- The UPDATE statement was not working when the WHERE clause contained some terms that could be satisfied using indices and other terms that could not. Fixed.

### 2001-02-11 (1.0.20)

- Merge development changes into the main trunk. Future work toward using a BTree file structure will use a separate CVS source tree. This CVS tree will continue to support the GDBM version of SQLite only.

### 2001-02-06 (1.0.19)

- Fix a strange (but valid) C declaration that was causing problems for QNX. No logical changes.

### 2001-01-04 (1.0.18)

- Print the offending SQL statement when an error occurs.
- Do not require commas between constraints in CREATE TABLE statements.
- Added the "-echo" option to the shell.
- Changes to comments.

### 2000-12-10 (1.0.17)

- Rewrote sqlite_complete() to make it faster.
- Minor tweaks to other code to make it run a little faster.
- Added new tests for sqlite_complete() and for memory leaks.

### 2000-11-28 (1.0.16)

- Documentation updates. Mostly fixing of typos and spelling errors.

### 2000-10-23 (1.0.15)

- Documentation updates
- Some sanity checking code was removed from the inner loop of vdbe.c to help the library to run a little faster. The code is only removed if you compile with -DNDEBUG.

### 2000-10-19 (1.0.14)

- Added a "memory:" backend driver that stores its database in an in-memory hash table.

### 2000-10-19 (1.0.13)

- Break out the GDBM driver into a separate file in anticipation to added new drivers.
- Allow the name of a database to be prefixed by the driver type. For now, the only driver type is "gdbm:".

### 2000-10-17 (1.0.12)

- Fixed an off-by-one error that was causing a coredump in the '%q' format directive of the new sqlite_..._printf() routines.
- Added the sqlite_interrupt() interface.
- In the shell, sqlite_interrupt() is invoked when the user presses Control-C
- Fixed some instances where sqlite_exec() was returning the wrong error code.

### 2000-10-11 (1.0.10)

- Added notes on how to compile for Windows95/98.
- Removed a few variables that were not being used. Etc.

### 2000-10-09 (1.0.9)

- Added the sqlite_..._printf() interface routines.
- Modified the sqlite shell program to use the new interface routines.
- Modified the sqlite shell program to print the schema for the built-in SQLITE_MASTER table, if explicitly requested.

### 2000-09-30 (1.0.8)

- Begin writing documentation on the TCL interface.

### 2000-09-29 (Not Released)

- Added the sqlite_get_table() API
- Updated the documentation for due to the above change.
- Modified the sqlite shell to make use of the new sqlite_get_table() API in order to print a list of tables in multiple columns, similar to the way "ls" prints filenames.
- Modified the sqlite shell to print a semicolon at the end of each CREATE statement in the output of the ".schema" command.

### 2000-09-21 (Not Released)

- Change the tclsqlite "eval" method to return a list of results if no callback script is specified.
- Change tclsqlite.c to use the Tcl_Obj interface
- Add tclsqlite.c to the libsqlite.a library

### 2000-09-14 (1.0.5)

- Changed the print format for floating point values from "%g" to "%.15g".
- Changed the comparison function so that numbers in exponential notation (ex: 1.234e+05) sort in numerical order.

### 2000-08-28 (1.0.4)

- Added functions length() and substr().
- Fix a bug in the sqlite shell program that was causing a coredump when the output mode was "column" and the first row of data contained a NULL.

### 2000-08-22 (1.0.3)

- In the sqlite shell, print the "Database opened READ ONLY" message to stderr instead of stdout.
- In the sqlite shell, now print the version number on initial startup.
- Add the sqlite_version[] string constant to the library
- Makefile updates
- Bug fix: incorrect VDBE code was being generated for the following circumstance: a query on an indexed table containing a WHERE clause with an IN operator that had a subquery on its right-hand side.

### 2000-08-18 (1.0.1)

- Fix a bug in the configure script.
- Minor revisions to the website.

### 2000-08-17 (1.0)

- Change the sqlite program so that it can read databases for which it lacks write permission. (It used to refuse all access if it could not write.)

### 2000-08-09

- Treat carriage returns as white space.

### 2000-08-08

- Added pattern matching to the ".table" command in the "sqlite" command shell.

### 2000-08-04

- Documentation updates
- Added "busy" and "timeout" methods to the Tcl interface

### 2000-08-03

- File format version number was being stored in sqlite_master.tcl multiple times. This was harmless, but unnecessary. It is now fixed.

### 2000-08-02

- The file format for indices was changed slightly in order to work around an inefficiency that can sometimes come up with GDBM when there are large indices having many entries with the same key. ** Incompatible Change **

### 2000-08-01

- The parser's stack was overflowing on a very long UPDATE statement. This is now fixed.

### 2000-07-31

- Finish the VDBE tutorial.
- Added documentation on compiling to WinNT.
- Fix a configuration program for WinNT.
- Fix a configuration problem for HPUX.

### 2000-07-29

- Better labels on column names of the result.

### 2000-07-28

- Added the sqlite_busy_handler() and sqlite_busy_timeout() interface.

### 2000-06-23

- Begin writing the VDBE tutorial.

### 2000-06-21

- Clean up comments and variable names. Changes to documentation. No functional changes to the code.

### 2000-06-19

- Column names in UPDATE statements were case sensitive. This mistake has now been fixed.

### 2000-06-18

- Added the concatenate string operator (||)

### 2000-06-12

- Added the fcnt() function to the SQL interpreter. The fcnt() function returns the number of database "Fetch" operations that have occurred. This function is designed for use in test scripts to verify that queries are efficient and appropriately optimized. Fcnt() has no other useful purpose, as far as I know.
- Added a bunch more tests that take advantage of the new fcnt() function. The new tests did not uncover any new problems.

### 2000-06-08

- Added lots of new test cases
- Fix a few bugs discovered while adding test cases
- Begin adding lots of new documentation

### 2000-06-06

- Added compound select operators: UNION, UNION ALL, INTERSECT, and EXCEPT
- Added support for using (SELECT ...) within expressions
- Added support for IN and BETWEEN operators
- Added support for GROUP BY and HAVING
- NULL values are now reported to the callback as a NULL pointer rather than an empty string.

### 2000-06-03

- Added support for default values on columns of a table.
- Improved test coverage. Fixed a few obscure bugs found by the improved tests.

### 2000-06-02

- All database files to be modified by an UPDATE, INSERT or DELETE are now locked before any changes are made to any files. This makes it safe (I think) to access the same database simultaneously from multiple processes.
- The code appears stable so we are now calling it "beta".

### 2000-06-01

- Better support for file locking so that two or more processes (or threads) can access the same database simultaneously. More work needed in this area, though.

### 2000-05-31

- Added support for aggregate functions (Ex: COUNT(*), MIN(...)) to the SELECT statement.
- Added support for SELECT DISTINCT ...

### 2000-05-30

- Added the LIKE operator.
- Added a GLOB operator: similar to LIKE but it uses Unix shell globbing wildcards instead of the '%' and '_' wildcards of SQL.
- Added the COPY command patterned after PostgreSQL so that SQLite can now read the output of the pg_dump database dump utility of PostgreSQL.
- Added a VACUUM command that calls the gdbm_reorganize() function on the underlying database files.
- And many, many bug fixes...

### 2000-05-29

- Initial Public Release of Alpha code