SQLite (32-bit) 歷史舊版本 Page3

更新時間：2018-06-05
更新細節：

What's new in this version:

- Add support for PostgreSQL-style UPSERT
- Add support for auxiliary columns in r-tree tables
- Add C-language APIs for discovering SQL keywords used by SQLite: sqlite3_keyword_count(), sqlite3_keyword_name(), and sqlite3_keyword_check()
- Add C-language APIs for dynamic strings based on the sqlite3_str object
- Enhance ALTER TABLE so that it recognizes "true" and "false" as valid arguments to DEFAULT
- Add the sorter-reference optimization as a compile-time option. Only available if compiled with SQLITE_ENABLE_SORTER_REFERENCES
- Improve the format of the EXPLAIN QUERY PLAN raw output, so that it gives better information about the query plan and about the relationships between the various components of the plan
- Added the SQLITE_DBCONFIG_RESET_DATABASE option to the sqlite3_db_config() API

CLI Enhancements:
- Automatically intercepts the raw EXPLAIN QUERY PLAN output and reformats it into an ASCII-art graph
- Lines that begin with "#" and that are not in the middle of an SQL statement are interpreted as comments
- Added the --append option to the ".backup" command
- Added the ".dbconfig" command

Performance:
- UPDATE avoids writing database pages that do not actually change. For example, "UPDATE t1 SET x=25 WHERE y=?" becomes a no-op if the value in column x is already 25. Similarly, when doing UPDATE on records that span multiple pages, only write the subset of pages that contain the changed value(s)
- Queries that use ORDER BY and LIMIT now try to avoid computing rows that cannot possibly come in under the LIMIT. This can greatly improve performance of ORDER BY LIMIT queries, especially when the LIMIT is small relative to the number of unrestricted output rows
- The OR optimization is allowed to proceed even if the OR expression has also been converted into an IN expression. Uses of the OR optimization are now also more clearly shown in the EXPLAIN QUERY PLAN output
- The query planner is more aggressive about using automatic indexes for views and subqueries for which it is not possible to create a persistent index
- Make use of the one-pass UPDATE and DELETE query plans in the R-Tree extension where appropriate
- Performance improvements in the LEMON-generated parser

Bug fixes:
- For the right-hand table of a LEFT JOIN, compute the values of expressions directly rather than loading precomputed values out of an expression index as the expression index might not contain the correct value. Ticket 7fa8049685b50b5aeb0c2
- Do not attempt to use terms from the WHERE clause to enable indexed lookup of the right-hand table of a LEFT JOIN. Ticket 4ba5abf65c5b0f9a96a7a
- Fix a memory leak that can occur following a failure to open error in the CSV virtual table
- Fix a long-standing problem wherein a corrupt schema on the sqlite_sequence table used by AUTOINCREMENT can lead to a crash. Ticket d8dc2b3a58cd5dc2918a1
- Fix the json_each() function so that it returns valid results on its "fullkey" column when the input is a simple value rather than an array or object.

Hashes:
- SQLITE_SOURCE_ID: "2018-06-04 19:24:41 c7ee0833225bfd8c5ec2f9bf62b97c4e04d03bd9566366d5221ac8fb199a87ca"
- SHA3-256 for sqlite3.c: 0d384704e1c66026228336d1e91771d295bf688c9c44c7a44f25a4c16c26ab3c

更新時間：2018-04-11
更新細節：

What's new in this version:

- Fix two problems in the new LEFT JOIN strength reduction optimization
- Fix misbehavior of the FTS5 xBestIndex method
- Fix a harmless reference to an uninitialized virtual machine register
- Fix the CLI so that it builds with -DSQLITE_UNTESTABLE
- Fix the eval.c extension so that it works with PRAGMA empty_result_callbacks=ON
- Fix the generate_series virtual table so that it correctly returns no rows if any of its constraints are NULL
- Performance enhancements in the parser

更新時間：2018-04-02
更新細節：

What's new in this version:

- Add the sqlite3_serialize() and sqlite3_deserialize() interfaces when the SQLITE_ENABLE_DESERIALIZE compile-time option is used
- Recognize TRUE and FALSE as constants. (For compatibility, if there exist columns named "true" or "false", then the identifiers refer to the columns rather than Boolean constants)
- Support operators IS TRUE, IS FALSE, IS NOT TRUE, and IS NOT FALSE
- Added the SQLITE_DBSTATUS_CACHE_SPILL option to sqlite3_db_status() for reporting the number of cache spills that have occurred
- The "alternate-form-2" flag ("!") on the built-in printf implementation now causes string substitutions to measure the width and precision in characters instead of bytes
- If the xColumn method in a virtual table implementation returns an error message using sqlite3_result_error() then give that error message preference over internally-generated messages
- Added the -A command-line option to the CLI to make it easier to manage SQLite Archive files
- Add support for INSERT OR REPLACE, INSERT OR IGNORE, and UPDATE OR REPLACE in the Zipfile virtual table
- Enhance the sqlite3changeset_apply() interface so that it is hardened against attacks from deliberately corrupted changeset objects
- Added the sqlite3_normalize() extension function

Query optimizer enhancements:
- Improve the omit-left-join optimization so that it works in cases where the right-hand table is UNIQUE but not necessarily NOT NULL
- Improve the push-down optimization so that it works for many LEFT JOINs
- Add the LEFT JOIN strength reduction optimization that converts a LEFT JOIN into an ordinary JOIN if there exist terms in the WHERE clause that would prevent the extra all-NULL row of the LEFT JOIN from appearing in the output set
- Avoid unnecessary writes to the sqlite_sequence table when an AUTOINCREMENT table is updated with an rowid that is less than the maximum

Bug fixes:
- Fix the parser to accept valid row value syntax
- Fix the query planner so that it takes into account dependencies in the arguments to table-valued functions in subexpressions in the WHERE clause
- Fix incorrect result with complex OR-connected WHERE and STAT4
- Fix potential corruption in indexes on expressions due to automatic datatype conversions
- Assertion fault in FTS4
- Incorrect result on the less-than operator in row values
- Always interpret non-zero floating-point values as TRUE, even if the integer part is zero
- Fix an issue in the fsdir(PATH) table-valued function to the fileio.c extension, that caused a segfault if the fsdir() table was used as the inner table of a join
- Issue an error rather instead of an assertion-fault or null-pointer dereference when the sqlite_master table is corrupted so that the sqlite_sequence table root page is really a btree-index page
- Fix the ANALYZE command so that it computes statistics on tables whose names begin with "sqlite"

Additional fixes for issues detected by OSSFuzz:
- Fix a possible infinite loop on VACUUM for corrupt database files
- Disallow parameters in the WITH clause of triggers and views
- Fix a potential memory leak in row value processing
- Improve the performance of the replace() SQL function for cases where there are many substitutions on megabyte-sized strings, in an attempt to avoid OSSFuzz timeouts during testing
- Provide an appropriate error message when the sqlite_master table contains a CREATE TABLE AS statement. Formerly this caused either an assertion fault or null pointer dereference. Problem found by OSSFuzz on the GDAL project
- Incorrect assert() statement removed
- Fix a problem with using the LIKE optimization on an INTEGER PRIMARY KEY

更新時間：2018-01-23
更新細節：

What's new in this version:

- The output of sqlite3_trace_v2() now shows each individual SQL statement run within a trigger
- Add the ability to read from WAL mode databases even if the application lacks write permission on the database and its containing directory, as long as the -shm and -wal files exist in that directory
- Added the rtreecheck() scalar SQL function to the R-Tree extension
- Added the sqlite3_vtab_nochange() and sqlite3_value_nochange() interfaces to help virtual table implementations optimize UPDATE operations
- Added the sqlite3_vtab_collation() interface
- Added support for the "^" initial token syntax in FTS5

New extensions:
- The Zipfile virtual table can read and write a ZIP Archive
- Added the fsdir(PATH) table-valued function to the fileio.c extension, for listing the files in a directory
- The sqlite_btreeinfo eponymous virtual table for introspecting and estimating the sizes of the btrees in a database
- The Append VFS is a VFS shim that allows an SQLite database to be appended to some other file. This allows (for example) a database to be appended to an executable that then opens and reads the database

Query planner enhancements:
- The optimization that uses an index to quickly compute an aggregate min() or max() is extended to work with indexes on expressions
- The decision of whether to implement a FROM-clause subquery as a co-routine or using query flattening now considers whether the result set of the outer query is "complex" (if it contains functions or expression subqueries). A complex result set biases the decision toward the use of co-routines
- The planner avoids query plans that use indexes with unknown collating functions
- The planner omits unused LEFT JOINs even if they are not the right-most joins of a query

Other performance optimizations:
- A smaller and faster implementation of text to floating-point conversion subroutine: sqlite3AtoF()
- The Lemon parser generator creates a faster parser
- Use the strcspn() C-library routine to speed up the LIKE and GLOB operators

Improvements to the command-line shell:
- The ".schema" command shows the structure of virtual tables
- Added support for reading and writing SQL Archive files using the .archive command
- Added the experimental .expert command
- Added the ".eqp trigger" variant of the ".eqp" command
- Enhance the ".lint fkey-indexes" command so that it works with WITHOUT ROWID tables
- If the filename argument to the shell is a ZIP archive rather than an SQLite database, then the shell automatically opens that ZIP archive using the Zipfile virtual table
- Added the edit() SQL function
- Added the .excel command to simplify exporting database content to a spreadsheet
- Databases are opened using Append VFS when the --append flag is used on the command line or with the .open command
- Enhance the SQLITE_ENABLE_UPDATE_DELETE_LIMIT compile-time option so that it works for WITHOUT ROWID tables
- Provide the sqlite_offset(X) SQL function that returns the byte offset into the database file to the beginning of the record holding value X, when compiling with -DSQLITE_ENABLE_OFFSET_SQL_FUNC

Bug fixes:
- Infinite loop on an UPDATE that uses an OR operator in the WHERE clause. Problem introduced with 3.17.0 and reported on the mailing list about one year later
- Incorrect query results when the skip-ahead-distinct optimization is used
- Incorrect query results on a join with a ORDER BY DESC
- Inconsistent result set column names between CREATE TABLE AS and a simple SELECT
- Assertion fault when doing REPLACE on an index on an expression
- Assertion fault when doing an IN operator on a constant index

更新時間：2017-10-25
更新細節：

What's new in this version:

- 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 PRAGMA reverse_unordered_selects
- 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
- Fix a potential out-of-bound read when querying a corrupt database file, a problem detected by Natalie Silvanovich of Google Project Zero

更新時間：2017-08-25
更新細節：

What's new in this version:

- Fix a potential memory leak in the new sqlite3_result_pointer() interface.

Changes carried forward from version 3.20.0:
- Update the text of error messages returned by sqlite3_errmsg() for some error codes
- Add new pointer passing interfaces
- Backwards-incompatible changes to some extensions in order to take advantage of the improved security offered by the new pointer passing interfaces: a. Extending FTS5 → requires sqlite3_bind_pointer() to find the fts5_api pointer
- carray(PTR,N) → requires sqlite3_bind_pointer() to set the PTR parameter
- remember(V,PTR) → requires sqlite3_bind_pointer() to set the PTR parameter
- Added the SQLITE_STMT virtual table extension
- Added the COMPLETION extension - designed to suggest tab-completions for interactive user interfaces. This is a work in progress. Expect further enhancements in future releases
- Added the UNION virtual table extension
- The built-in date and time functions have been enhanced so that they can be used in CHECK constraints, in indexes on expressions, and in the WHERE clauses of partial indexes, provided that they do not use the 'now', 'localtime', or 'utc' keywords. Futher information
- Added the sqlite3_prepare_v3() and sqlite3_prepare16_v3() interfaces with the extra "prepFlags" parameters
- Provide the SQLITE_PREPARE_PERSISTENT flag for sqlite3_prepare_v3() and use it to limit lookaside memory misuse by FTS3, FTS5, and the R-Tree extension
- Added the PRAGMA secure_delete=FAST command. When secure_delete is set to FAST, old content is overwritten with zeros as long as that does not increase the amount of I/O. Deleted content might still persist on the free-page list but will be purged from all b-tree pages
- Enhancements to the command-line shell: a. Add support for tab-completion using the COMPLETION extension, for both readline and linenoise
- Add the ".cd" command
- Enhance the ".schema" command to show the schema of all attached databases
- Enhance ".tables" so that it shows the schema names for all attached if the name is anything other than "main"
- The ".import" command ignores an initial UTF-8 BOM
- Added the "--newlines" option to the ".dump" command to cause U+000a and U+000d characters to be output literally rather than escaped using the replace() function
- Query planner enhancements: a. When generating individual loops for each ORed term of an OR scan, move any constant WHERE expressions outside of the loop, as is done for top-level loops
- The query planner examines the values of bound parameters to help determine if a partial index is usable
- When deciding between two plans with the same estimated cost, bias the selection toward the one that does not use the sorter
- Evaluate WHERE clause constraints involving correlated subqueries last, in the hope that they never have be evaluated at all
- Do not use the flattening optimization for a sub-query on the RHS of a LEFT JOIN if that subquery reads data from a virtual table as doing so prevents the query planner from creating automatic indexes on the results of the sub-query, which can slow down the query
- Add SQLITE_STMTSTATUS_REPREPARE, SQLITE_STMTSTATUS_RUN, and SQLITE_STMTSTATUS_MEMUSED options for the sqlite3_stmt_status() interface
- Provide PRAGMA functions for PRAGMA integrity_check, PRAGMA quick_check, and PRAGMA foreign_key_check
- Add the -withoutnulls option to the TCL interface eval method
- Enhance the sqlite3_analyzer.exe utility program so that it shows the number of bytes of metadata on btree pages
- The SQLITE_DBCONFIG_ENABLE_QPSG run-time option and the SQLITE_ENABLE_QPSG compile-time option enable the query planner stability guarantee
- Miscellaneous optimizations result in a 2% reduction in CPU cycles used

Bug Fixes:
- Fix the behavior of sqlite3_column_name() for queries that use the flattening optimization so that the result is consistent with other queries that do not use that optimization, and with PostgreSQL, MySQL, and SQLServer
- Fix the query planner so that it knows not to use automatic indexes on the right table of LEFT JOIN if the WHERE clause uses the IS operator
- Ensure that the query planner knows that any column of a flattened LEFT JOIN can be NULL even if that column is labeled with "NOT NULL"
- Fix rare false-positives in PRAGMA integrity_check when run on a database connection with attached databases
- Fix a bug (discovered by OSSFuzz) that causes an assertion fault if certain dodgy CREATE TABLE declarations are used

更新時間：2017-08-02
更新細節：

What's new in this version:

- Update the text of error messages returned by sqlite3_errmsg() for some error codes
- Add new pointer passing interfaces

Backwards-incompatible changes to some extensions in order to take advantage of the improved security offered by the new pointer passing interfaces:
- Extending FTS5 → requires sqlite3_bind_pointer() to find the fts5_api pointer
- carray(PTR,N) → requires sqlite3_bind_pointer() to set the PTR parameter
- remember(V,PTR) → requires sqlite3_bind_pointer() to set the PTR parameter
- Added the SQLITE_STMT virtual table extension
- Added the COMPLETION extension - designed to suggest tab-completions for interactive user interfaces. This is a work in progress. Expect further enhancements in future releases
- Added the UNION virtual table extension
- The built-in date and time functions have been enhanced so that they can be used in CHECK constraints, in indexes on expressions, and in the WHERE clauses of partial indexes, provided that they do not use the 'now', 'localtime', or 'utc' keywords. Futher information
- Added the sqlite3_prepare_v3() and sqlite3_prepare16_v3() interfaces with the extra "prepFlags" parameters
- Provide the SQLITE_PREPARE_PERSISTENT flag for sqlite3_prepare_v3() and use it to limit lookaside memory misuse by FTS3, FTS5, and the R-Tree extension
- Added the PRAGMA secure_delete=FAST command. When secure_delete is set to FAST, old content is overwritten with zeros as long as that does not increase the amount of I/O. Deleted content might still persist on the free-page list but will be purged from all b-tree pages

Enhancements to the command-line shell:
- Add support for tab-completion using the COMPLETION extension, for both readline and linenoise
- Add the ".cd" command
- Enhance the ".schema" command to show the schema of all attached databases
- Enhance ".tables" so that it shows the schema names for all attached if the name is anything other than "main"
- The ".import" command ignores an initial UTF-8 BOM
- Added the "--newlines" option to the ".dump" command to cause U+000a and U+000d characters to be output literally rather than escaped using the replace() function

Query planner enhancements:
- When generating individual loops for each ORed term of an OR scan, move any constant WHERE expressions outside of the loop, as is done for top-level loops
- The query planner examines the values of bound parameters to help determine if a partial index is usable
- When deciding between two plans with the same estimated cost, bias the selection toward the one that does not use the sorter
- Evaluate WHERE clause constraints involving correlated subqueries last, in the hope that they never have be evaluated at all
- Do not use the flattening optimization for a sub-query on the RHS of a LEFT JOIN if that subquery reads data from a virtual table as doing so prevents the query planner from creating automatic indexes on the results of the sub-query, which can slow down the query
- Add SQLITE_STMTSTATUS_REPREPARE, SQLITE_STMTSTATUS_RUN, and SQLITE_STMTSTATUS_MEMUSED options for the sqlite3_stmt_status() interface
- Provide PRAGMA functions for PRAGMA integrity_check, PRAGMA quick_check, and PRAGMA foreign_key_check
- Add the -withoutnulls option to the TCL interface eval method
- Enhance the sqlite3_analyzer.exe utility program so that it shows the number of bytes of metadata on btree pages
- The SQLITE_DBCONFIG_ENABLE_QPSG run-time option and the SQLITE_ENABLE_QPSG compile-time option enable the query planner stability guarantee. See also ticket 892fc34f173e99d8
- Miscellaneous optimizations result in a 2% reduction in CPU cycles used

Bug Fixes:
- Fix the behavior of sqlite3_column_name() for queries that use the flattening optimization so that the result is consistent with other queries that do not use that optimization, and with PostgreSQL, MySQL, and SQLServer
- Fix the query planner so that it knows not to use automatic indexes on the right table of LEFT JOIN if the WHERE clause uses the IS operator
- Ensure that the query planner knows that any column of a flattened LEFT JOIN can be NULL even if that column is labeled with "NOT NULL"
- Fix rare false-positives in PRAGMA integrity_check when run on a database connection with attached databases
- Fix a bug (discovered by OSSFuzz) that causes an assertion fault if certain dodgy CREATE TABLE declarations are used

更新時間：2017-06-09
更新細節：

What's new in this version:

- Fix a bug associated with auto_vacuum that can lead to database corruption. The bug was introduced in version 3.16.0 (2017-01-02). Ticket fda22108

更新時間：2017-05-26
更新細節：

What's new in this version:

- Fix more bugs in the LEFT JOIN flattening optimization

更新時間：2017-05-25
更新細節：

What's new in this version:

- Fix a bug in the LEFT JOIN flattener optimization
- Remove a surplus semicolon that was causing problems for older versions of MSVC