• Fix a bug that could result in database corruption 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.

• Fix for a bug in the ORDER BY optimizer that was introduced in DISQLite3 4.1.2 which would sometimes optimize out the sorting step when in fact the sort was required.
• 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.
• Fix a bug in the NEAR operator of FTS3 when applied to subfields.
• 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.
• 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.
• Improved error messages in the RTREE extension.
• Improved error messages for "foreign key mismatch" showing the names of the two tables involved.
• 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.
• 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.
• DISQLite3Database: Remove deprecated functions and procedures.
• DISQLite3Database: User helper functions and procedures from DIUtils to remove duplicates.

• Fix a bug that causes an ORDER BY clause to be optimized out of a three-way join when the ORDER BY is actually required.

• Fix a bug, introduced in DISQLite3 4.1.0, 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.

• Added the sqlite3_errstr interface.
• Avoid invoking the sqlite3_trace callback multiple times when a statement is automatically reprepared due to SQLITE_SCHEMA errors.
• 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.
• 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.
• 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 Encryption Extension are all used at once.
• 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.

• Support Delphi XE3 Win32 and Win64.
• Add the sqlite3_close_v2 interface.
• 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.
• Better handling of aggregate queries where the aggregate functions are contained within subqueries.
• Enhance the query planner so that it tries to use a covering index on queries that make use of or optimization.

• 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 reseting 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.
• 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.
• New FTS3 / FTS4 unicode61 tokenizer with full unicode case folding according to rules in Unicode Version 6.1 and recognizes unicode space and punctuation characters and uses those to separate tokens.

• Fix a bug introduced in DISQLite3 3.1.4 that can cause a segfault for certain obscure nested aggregate queries.

• 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.
• 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 (DISQLite3 Source Code edition only).
• Enhance the PRAGMA integrity_check command to use much less memory when processing multi-gigabyte databases.
• 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 DISQLite3 3.1.3.
• 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.
• Do not optimize away an ORDER BY clause that has the same terms as a UNIQUE index unless those terms are also NOT NULL.
• Add TParam filtering to the DISQLite3_ClientDataSet_Grid demo project.

• 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 DISQLite3 3.1.1 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.
• Fix a bug introduced in SQLite3 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.

• 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), DISQLite3 1.2.4 (2005-12-28). 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 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.
• Change the windows VFS to report a sector size of 4096 instead of the old default of 512.
• 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.
• Bug fix: Change the VDBE so that all registers are initialized to Invalid instead of NULL.
• Bug fix: Fix problems that can result from 32-bit integer overflow.

• The FTS4 full-text search engine has been enhanced such that tokens in the search string (on the right-hand side of the MATCH operator) that begin with "^" must be the first token in their respective columns in order to match. Potentially Incompatible Change: Formerly, "^" characters in the search string were simply ignored. Hence, if a legacy application was including "^" characters in FTS4 search strings, thinking that they would always be ignored, then those legacy applications might break with this update. The fix is simply remove the "^" characters from the search string.
• Added options SQLITE_DBSTATUS_CACHE_HIT and SQLITE_DBSTATUS_CACHE_MISS to the sqlite3_db_status interface.
• Improved ANALYZE now creates the sqlite_stat3 table, a much more capbable enhancement of the previous sqlite_stat2.
• 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.
• Overflow pages can now be read directly from the database file, bypassing the page cache. This might improve read performance of large BLOBs (DISQLite3 Pro only).
• 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 | 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.
• New "external merge sort" algorithm used to implement ORDER BY and GROUP BY and also to presort the content of an index for CREATE INDEX (DISQLite3 Pro only). The new algorithm does approximately the same number of comparisons and I/Os as before, but the I/Os are much more sequential and so runtimes are greatly reduced when the size of the set being sorted is larger than the filesystem cache. The performance improvement can be dramatic – orders of magnitude faster for large CREATE INDEX commands. On the other hand, the code is slightly slower (1% or 2%) for a small CREATE INDEX. Since CREATE INDEX is not an operation that commonly occurs on a speed-critical path, we feel that this tradeoff is a good one. The slight slowdown for small CREATE INDEX statements might be recovered in a future release. ORDER BY and GROUP BY operations should now be faster for all cases, large and small.
• Improved the windows VFS to better defend against interference from anti-virus software.
• Improved query plan optimization when the DISTINCT keyword is present on SELECT statements.
• Increase the default size of a lookahead cache line from 100 to 128 bytes.
• 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.

• Support Delphi XE2 Win64.
• SQLite's ATTACH stopped to recognize the DISQLite3 encryption codec so no password was set for attached databases. Fixed.
• Fix buffer allocation in Demos\DISQLite3_Full_Text_Search\DISQLite3Tokenizer.pas. Long tokens were not recognized at full length.
• Add column sorting to the DISQLite3_Full_Text_Search demo.

• Support Delphi XE2 Win32.
• Add DISQLite3_FastReport demo project.

• Add support for URI filenames. URI filenames are disabled by default (for backwards compatibility) but applications are encouraged to enable them since incompatibilities are likely to be exceedingly rare and the feature is useful.
• Add the sqlite3_vtab_config interface in support of ON CONFLICT clauses with virtual tables.
• The virtual table interface has been enhanced to support SAVEPOINT and ON CONFLICT clause processing, and the built-in RTREE and FTS3/FTS4 have been augmented to take advantage of the new capability. This means, for example, that it is now possible to use the REPLACE command on FTS3/FTS4 and RTREE tables.
• 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.
• 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 DISQLite3 comes under memory pressure.

• Integer arithmetic operations that would have resulted in overflow are now performed using floating-point instead.
• New "fuzzer" Virtual Table (DISQLite3 Pro only).
• New "wholenumber" Virtual Table.
• Increased the version number on the VFS object to 3 and added new methods xSetSysCall, xGetSysCall, and xNextSysCall used for testing.
• Increase the maximum number of attached databases from 30 to 62, even though the default value remains at 10.
• Enhance the ANALYZE command to support the name of an index as its argument, in order to analyze just that one index.

This is an intermediate release based on an a pre SQLite 3.7.6 snapshot. Recommended only to make use of the newly added functionality.

• Enable support for loadable extensions. Extension modules may be build using DISQLite3Ext.
• 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.
• 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.
• Enhancements to FTS4: Add the compress and uncompres options and direct access to the full-text index.
• Bug fixes.

• Added the SQLITE_DBSTATUS_LOOKASIDE_HIT, SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE, and SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL options for the sqlite3_db_status interface.
• Updates to sqlite3_stmt_readonly so that its result is well-defined for all prepared statements and so that it works with VACUUM.
• 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.
• Testing shows that this release is about 1% or 2% faster than the previous release for most operations.

• Added the sqlite3_blob_reopen interface to allow an existing sqlite3_blob object to be rebound to a new row. Also use this to improve the performance of FTS3.
• Added the sqlite3_create_function_v2 interface that includes a destructor callback.
• VFSes that do not support shared memory are allowed to access WAL databases if PRAGMA locking_mode is set to EXCLUSIVE.
• Added support for custom r-tree queries using application-supplied callback routines to define the boundary of the query region.
• 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 sqlite3_soft_heap_limit64 interface as a replacement for sqlite3_soft_heap_limit.
• 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 defined at compile time.
• 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.
• A very obscure bug associated with the or optimization was fixed.
• Miscellaneous documentation enhancements.

• Delphi XE support.
• Add thread safety to help index and update FAQ.

• Fix an old and very obscure bug that can lead to corruption of the database free-page list when incremental_vacuum is used multiple times to partially reduce the size of a database file that contains many hundreds of unused database pages. The bug is impossible to hit without using incremental_vacuum and is very difficult to hit even with incremental_vacuum. And the kind of corruption that the bug causes can usually be fixed simply by running VACUUM.
• 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. A database with 64KiB pages will not be readable or writable by older versions of SQLite. Note that further increases in page size are not feasible since the file format uses 16-bit offsets to structures within each page.
• 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, 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 regresssions relative to SQLite 3.6.23.1 on some complex joins.
• Performance improvement to TDISQLite3Database.Execute when processing very large SQL scripts.

• Fix a potential database corruption problem that can result if the same database file is alternately written by DISQLite3 version 2.3.0 (SQLite version 3.7.0) and DISQLite3 2.2.2 (SQLite 3.6.23.1) or earlier.
• Fix a possible performance regression caused by the introduction of automatic indexing.

The differences between DISQLite3 2.3.0.1 and DISQLite3 2.3.0 are minimal, but because of the possibility of database corruption, upgrading is highly recommended.

• Added support for write-ahead logging (DISQLite3 Pro only).
• 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.

• 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.
• Fix that INSERTing into an RTREE returns the correct sqlite3_last_insert_rowid.
• Correctly handle strings with zero tokens in the FTS3 offsets() function.
• Enhance FTS3 to take advantage of the MAX() optimization.
• Improved error message when the right-hand operand of MATCH in FTS3 is not a valid search expression.
• Fix crash compiling "INSERT INTO tbl DEFAULT VALUES" if tbl has BEFORE or INSTEAD OF triggers.
• Fix an out of memory error on ANALYZE with STAT2 enabled with zero-length data.

• 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.
• Improvements to FTS3.
• The integrity_check pragma is enhanced to detect out-of-order rowids.
• Various minor bug fixes and performance enhancements.
• Completely revised the help generator to ease navigation and improve readability. Send your comments!

IMPORTANT INCOMPATIBILITY CHANGE – please read carefully:

Up to this version, the sqlite3 type was an untyped Pointer. This worked fine when used correctly, but caused hard to identify errors when not. Incompatible variable types are usually detected by the compiler's type checking. But as a matter of fact, Delphi does not generate type errors for untyped Pointer. Code would compile happily if sqlite3 was used instead of sqlite3_stmt, and Delphi would not even object to TDISQLite3Database in place of sqlite3.

Instead, problems surfaced at runtime. They often materialized as access violations with no meaningful error message and could drive helpless developers into despair. When contacting support, some of them even attributed the problem to a bug in DISQLite3. Even though this was not correct, they certainly had a point. So after careful consideration I decided to change all untyped Pointer types to pointers to record structures.

For record pointers, Delphi can detect type conflicts at compile time, so the likelihood of critical runtime errors is greatly reduced. For most stringent type checking, I recommend to compile with "Typed @ operator" always enabled. This can be set as a project option or in code using {$T+} or {$TYPEDADDRESS ON}. With typed @ operator enabled, Delphi also detects incompatible output variable types passed to sqlite3_open, sqlite3_prepare_v2, and similar routines.

Unfortunately, the modified strong typing might ask to change existing code before it compiles. Luckily, however, with {$TYPEDADDRESS ON} Delphi now catches all type incompatibilities so they can be fixed easily. For smaller projects, this is a simple search and replace (older IDEs) or code refactoring (newer ones).

Automatic conversion for larger projects is at hand here:

• http://www.yunqa.de/delphi/downloads/DISQLite3_Type_Converter.zip

DISQLite3_Type_Converter.zip contains a precompiled version of the JVCLConverter utility plus the conversion data file. It takes less than a minute to update the DISQLite3 Demos from previous versions: Run JVCLConverter.exe, select the source code folder, and convert. Converting other projects should be just as quickly.

Limit to auto-conversion: The PPointerArray type (mostly used in sqlite3_create_function callbacks) is a standard Delphi type. Converting this automatically might cause unintended side effects if used outside the DISQLite3 context. Therefore PPointerArray must be manually changed to sqlite3_value_ptr_array_ptr.

This table lists all modified, renamed, or deleted type names and their new counterparts. Only those at the top of the list should be in frequent use:

Bugs fixed in this version:

• Problems that might cause incorrect query results:
  • Queries that have a WHERE clause of the form (x AND y) OR z where x and z come from one table of a join and y comes from a different table.
  • Queries where the use of the CAST operator in the WHERE clause could lead to incorrect results if the column being cast to a new datatype is also used in the same WHERE clause without being cast.
  • Expressions with different COLLATIONs could compare equal and lead to wrong query results.
• When reusing an instance of TDISQLite3Database, the internal transaction counter was not reset when opening another database so its InTransaction property could return wrong results. Fixed.
• Other minor bug fixes and performance enhancements, especially for the FTS3 full text search.

• The SQL output resulting from sqlite3_trace is now modified to include the values of bound parameters.
• Optimizer enhancement: prepared statements are automatically re-compiled when a binding on the right hand side of a LIKE operator changes or when any range constraint changes for analyzed tables.
• Performance optimizations (12% reduction in the number of CPU operations) targetting specific use cases. Changes include the ifnull(), coalesce(), and substr() SQL functions plus various code refactorizations.
• More flexible Unicode tokenizer for the DISQLite3_Full_Text_Search demo. Added option for word stemming in 15 languages using YuStemmer.
• New FTS3 documentation is now available.
• Various minor bug fixes and documentation enhancements.
• New DISQLite3_Backup demo is a fully functional console application to back up any "hot" SQLite database.

• Native 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.
• Recursive triggers support. The older non-recursive behavior of triggers is still the default behavior. Recursive triggers are activated using the recursive_triggers pragma. In addition to allowing triggers to call themselves (either directly or indirectly) the new capability also fires DELETE triggers on rows that are removed from a table as a result of REPLACE conflict resolution processing. Non-recursive triggers are still the default behavior since this is least likely to cause problems for existing applications. However, it is anticipated that triggers will become recursive by default sometime in the future. At that point, applications that want to continue using the older non- recursive trigger behavior will need to use the recursive_triggers pragma to disable recursive triggers.
• Refinements to the query planner that help to choose better plans for joins where in the past it was selecting suboptimal query plans. Running the ANALYZE command will collect histogram data on indices. The use of histograms improves the query planning performance even more.
• 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: New sqlite3_sourceid interface and SQL function sqlite_source_id().
• Obscure bug fix on triggers, plus other bux fixes.

• Delphi 2010 support.
• Fix a threading issue with TDISQLite3Database by wrapping all calls to its FStatements field with mutexes.
• Fix sqlite3_key so that it successfully sets a correct password after an incorrect one.

• Mark sqlite3_prepare and sqlite3_prepare16 as deprecated. They are retained for backwards compatibility, but their use is discounraged. Instead, sqlite3_prepare_v2 and sqlite3_prepare16_v2 should be used, which work much better with SQLITE_SCHEMA errors.
• 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.
• Modify FTS3 so that in terms like 'column_name:token' the column_name is interpreted in a case-insenstive fashion.
• Fix a double-free that can occur when using the FTS3 '-' operator.
• Other minor bug fixes.

• Fix a bug that occasionally causes INSERT or UPDATE operations to fail on an indexed table that has a self-modifying trigger.
• Internal representation of SQL expressions use less memory.
• Reduce the amount of stack space used.
• 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.
• Enhanced robustness against corrupt database files.
• Fix a code generator bug that can cause incorrect query results under obscure circumstances.
• Fix a bug in group_concat().
• Fix a performance bug in the pager cache.
• Fix a bug in the sqlite3_backup implementation that can lead to a corrupt backup database.
• Allow empty TDISQLite3Database.DatabaseName to create temporary databases. A warning is issued a design time.
• Other minor bug fixes and performance optimizations.

• New asynchronous backend module (DISQLite3 Pro only). It gives the illusion of faster response times by pushing slow write operations into a background thread. The tradeoff for faster response time is that more memory is required (to hold the content of the pending writes) and if a power failure or program crash occurs, some transactions that appeared to have committed might end up being rolled back upon restart.
• Performance enhancements in the btree and pager layers and in the query optimizer. Certain workloads can be as much as twice as fast as the previous release, though 10% faster is a more typical result.
• Enhanced the query optimizer so that queries against virtual tables that contain OR and IN operators in the WHERE clause are now able to use indexes.
• Many minor bug fixes.

• Fix a bug that causesd a segfault when running a count(*) on the sqlite_master table of an empty database.
• Fix a bug that causesd a segfault that when inserting into a table using a DEFAULT value where there is a function as part of the DEFAULT value expression.
• Other minor bug fixes.

• Fixed a bug that caused database corruption when an incremental_vacuum is rolled back in an in-memory database. If an incremental_vacuum was rolled back in an in-memory database, the database would often go corrupt. This only happened for in-memory databases. On-disk databases were unaffected. And the corruption only appeared if an incremental vacuum was rolled back. Upgrading is recommended for all applications, especially those that make use of in-memory databases and/or incremental vacuum.
• Fixed a bug in the lookaside memory allocator relating to shared cache mode. If a database connection closed before others, it could prematurely deallocate critical elements of the shared schema.
• Added the sqlite3_unlock_notify interface (DISQLite3 Pro only).
• Added the reverse_unordered_selects pragma (DISQLite3 Pro only).
• The default page size is automatically adjusted to match the capabilities of the underlying filesystem.
• Performance improvements for "count(*)" queries (DISQLite3 Pro only).
• Reduce the amount of heap memory used, especially by TRIGGERs.

• New Hot Backup Interface (DISQLite3 Pro only).
• Improve TDISQLite3UniDirQuery Provider Support when inserting and updating BLOB fields with #0 values and NULL BLOBs.
• For PRIMATY KEY columns, Use the ftAutoInc field type and exclude pfInUpdate from ProviderFlags in TDISQLite3UniDirQuery. This helps to handle multiple insert problems with TClientDataSet.
• Update DISQLite3_ClientDataSet_Grid.dpr demo to use decreasing negative RowIDs so multiple inserts do not conflict.
• Various minor bug fixes.
• Type changes to sqlite3_context and sqlite3_context_ptr. This an unfortunate incompatibility change. To find out if you are affected, recompile your code and watch for compiler errors. If so, update your code by replacing "sqlite3_context" with "sqlite3_context_ptr".
• Improvements to the syntax bubble diagrams.

• 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 (source code only).
• Fix a cache coherency problem that could lead to database corruption.
• 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.

• Add TDISQLite3UniDirQuery support for TClientDataSet.RefreshRecord.
• Fixes for various minor bugs.

• Fix a bug in the b-tree delete algorithm that seems like it might be able to cause database corruption.
• Fix a memory leak that can occur following a disk I/O error.
• Fix a bug in the page cache that can lead database corruption following a rollback.
• Add the application-defined page cache.
• TDISQLite3UniDirQuery now sets the TField.Required property for columns declared as NOT NULL.
• Add the TDISQLite3DataSetImporter.OnImportError event to catch and log exceptions (which may be caused by, for example, invalid data conversions on certain records) and continue the import.
• Also in TDISQLite3DataSetImporter, call the progress event for every single record instead of every 16th one only.
• Fix a memory overrun in TDISQLite3DataSetImporter in the line wrap functions for textual blob data.
• Other minor bug fixes and optimizations.

• Delphi 2009 support.
• Add the MEMORY option to PRAGMA journal_mode.
• Added the sqlite3_db_mutex interface.
• 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.
• Add option support for LIMIT and ORDER BY clauses on DELETE and UPDATE statements (DISQLite3 Professional only).
• Added the sqlite3_stmt_status interface for performance monitoring.
• Add the INDEXED BY clause.
• Added the TRUNCATE option to PRAGMA journal_mode
• Performance enhancements to tree balancing logic in the B-Tree layer.
• The SQL language documentation is converted to use syntax diagrams instead of BNF.
• Bug fixes

• 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.
• Numerious other performance enhancements
• Miscellaneous minor bug fixes