*** DRAFT ***
SQLite Release 3.21.0 On 2017-10-25
- Take advantage of the atomic-write capabilities in the
F2FS filesystem when available, for
greatly reduced transaction overhead. This currently requires the
SQLITE_ENABLE_BATCH_ATOMIC_WRITE compile-time option.
- Allow ATTACH and DETACH commands to work inside of a transaction.
- Allow WITHOUT ROWID virtual tables to be writable if the PRIMARY KEY
contains exactly one column.
- The "fsync()" that occurs after the header is written in a WAL reset
now uses the sync settings for checkpoints. This means it will use a
"fullfsync" on macs if PRAGMA checkpoint_fullfsync set on.
- The sqlite3_sourceid() function tries to detect if the source code has
been modified from what is checked into version control and if there are
modifications, the last four characters of the version hash are shown as
"alt1" or "alt2". The objective is to detect accidental and/or careless
edits. A forger can subvert this feature.
- Improved de-quoting of column names for CREATE TABLE AS statements with
an aggregate query on the right-hand side.
- Fewer "stat()" system calls issued by the unix VFS.
- Enhanced the LIKE optimization so that it works with an ESCAPE clause.
- Enhanced PRAGMA integrity_check and PRAGMA quick_check to detect obscure
row corruption that they were formerly missing. Also update both pragmas
so that they return error text rather than SQLITE_CORRUPT when encountering
corruption in records.
- The query planner now prefers to implement FROM-clause subqueries using
co-routines rather using the query flattener optimization. Support for
the use of co-routines for subqueries may no longer be disabled.
- Pass information about !=, IS, IS NOT, NOT NULL, and IS NULL constraints
into the xBestIndex method of virtual tables.
- Enhanced the CSV virtual table so that it accepts the last row of
input if the final new-line character is missing.
- Remove the rarely-used "scratch" memory allocator. Replace it with the
SQLITE_CONFIG_SMALL_MALLOC configuration setting that gives SQLite
a hint that large memory allocations should be avoided when possible.
- Added the
swarm virtual table
to the existing union virtual table extension.
- Added the
sqlite_dbpage virtual table
for providing direct access to pages
of the database file. The source code is built into the amalgamation and
is activated using the -DSQLITE_ENABLE_DBPAGE_VTAB compile-time option.
- Add a new type of fts5vocab virtual table - "instance" - that provides
direct access to an FTS5 full-text index at the lowest possible level.
- Remove a call to rand_s() in the Windows VFS since it was causing problems
in Firefox on some older laptops.
- The src/shell.c source code
to the command-line shell is no longer under version control. That file
is now generated as part of the build process.
- Miscellaneous microoptimizations reduce CPU usage by about 2.1%.
- Bug fixes:
- Fix a faulty assert() statement discovered by OSSFuzz.
- Fix an obscure memory leak in sqlite3_result_pointer().
- Avoid a possible use-after-free error by deferring schema resets until
after the query planner has finished running.
- Only use indexes-on-expressions to optimize ORDER BY or GROUP BY if
the COLLATE is correct.
- Fix an assertion fault that was coming up when the expression in an
index-on-expressions is really a constant.
- Fix an assertion fault that could occur following
- Fix a segfault that can occur for queries that use table-valued functions
in an IN or EXISTS subquery.
- Fix a potential integer overflow problem when compiling a particular
horrendous common table expression. This was another problem discovered
by OSSFuzz. Check-in 6ee8cb6ae5.
- Fix a potential out-of-bound read when querying a corrupt database file,
a problem detected by Natalie Silvanovich of Google Project Zero.
A complete list of SQLite releases
in a single page and a chronology are both also available.
A detailed history of every
check-in is available at
SQLite version control site.
*** DRAFT ***