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Overview
| Comment: | Begin a change log entry for the 3.21.0 release. |
|---|---|
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA3-256: |
4cadcc5b9c5eda7860e784e900d19ff6 |
| User & Date: | drh 2017-08-03 20:39:01 |
Context
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2017-08-04
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| 14:25 | Add the 2009-2018 speed graph relative to 3.20.0 to the speed-size spreadsheet. check-in: 4df296b435 user: drh tags: trunk | |
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2017-08-03
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| 20:39 | Begin a change log entry for the 3.21.0 release. check-in: 4cadcc5b9c user: drh tags: trunk | |
| 15:47 | Fix another typo in the bindptr.html document. check-in: 8d2c7aa89d user: drh tags: trunk | |
Changes
Changes to pages/changes.in.
16 16 set nChng 0 17 17 proc chng {date desc {options {}}} { 18 18 global nChng aChng xrefChng 19 19 set aChng($nChng) [list $date $desc $options] 20 20 set xrefChng($date) $nChng 21 21 incr nChng 22 22 } 23 + 24 +chng {2017-11-01 (3.21.0)} { 25 +<li> Take advantage of the atomic-write capabilities of the 26 + [https://en.wikipedia.org/wiki/F2FS|F2FS filesystem] when available, for 27 + greatly reduced transaction overhead. This currently requires the 28 + [SQLITE_ENABLE_BATCH_ATOMIC_WRITE] compile-time option. 29 +<li> Allow [ATTACH] and [DETACH] commands to work inside of a transaction. 30 +<li> Query planner enhancements: 31 +<ol type="a"> 32 +<li> Enhanced the [LIKE optimization] so that it works with an ESCAPE clause. 33 +</ol> 34 +<li> Miscellaneous [microoptimizations] reduce CPU usage by about 0.4%. 35 +<li> Bug fixes: 36 +<ol type="a"> 37 +<li> Fix a faulty assert() statement discovered by OSSFuzz. 38 + Ticket [https://sqlite.org/src/info/cb91bf4290c211d|cb91bf4290c211d] 39 +</ol> 40 +} 23 41 24 42 chng {2017-08-01 (3.20.0)} { 25 43 <li> Update the text of error messages returned by [sqlite3_errmsg()] for some 26 44 error codes. 27 45 <li> Add new [pointer passing interfaces]. 28 46 <li> Backwards-incompatible changes to some extensions in order to take 29 47 advantage of the improved security offered by the new
Changes to pages/chronology.in.
24 24 # ORDER BY mtime DESC; 25 25 # 26 26 # A small amount of manual editing and de-duplication followed. 27 27 # 28 28 # Manually edit the list for each subsequent release. 29 29 # 30 30 foreach line [split { 31 +xxxxxxxxxx|pending|Version 3.21.0 31 32 9501e22dfe|2017-08-01|Version 3.20.0 32 33 036ebf729e|2017-06-17|Version 3.18.2 33 34 77bb46233d|2017-06-16|Version 3.18.1 34 35 0ee482a1e0|2017-06-08|Version 3.19.3 35 36 edb4e819b0|2017-05-25|Version 3.19.2 36 37 f6d7b988f4|2017-05-24|Version 3.19.1 37 38 28a94eb282|2017-05-22|Version 3.19.0
Changes to pages/compile.in.
766 766 or written. On filesystems that support atomic writes, this 767 767 optimization can result in significant speed improvements for 768 768 small updates. However, few filesystems support this capability 769 769 and the code paths that check for this capability slow down write 770 770 performance on systems that lack atomic write capability, so this 771 771 feature is disabled by default. 772 772 } 773 + 774 +COMPILE_OPTION {SQLITE_ENABLE_BATCH_ATOMIC_WRITE} { 775 + This compile-time option enables SQLite to take advantage batch 776 + atomic write capabilities in the underlying filesystem. As of 777 + SQLite version 3.21.0 ([dateof:3.21.0]) this is only supported on 778 + [https://en.wikipedia.org/wiki/F2FS|F2FS]. However, the interface 779 + is implemented generically, using [sqlite3_file_control()] with 780 + [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] 781 + so the capability can be added to other filesystem times in the 782 + future. When this option is enabled, SQLite automatically detects 783 + that the underlying filesystem supports batch atomic writes, and 784 + when it does so it avoids writing the [rollback journal] for transaction 785 + control. This can make transactions over twice as fast, while 786 + simultaneously reducing wear on SSD storage devices. 787 +<p> 788 + Future versions of SQLite might enable the batch-atomic-write 789 + capability by default, at which point this compile-time option 790 + will become superfluous. 791 +} 773 792 774 793 COMPILE_OPTION {SQLITE_ENABLE_COLUMN_METADATA} { 775 794 When this C-preprocessor macro is defined, SQLite includes some 776 795 additional APIs that provide convenient access to meta-data about 777 796 tables and queries. The APIs that are enabled by this option are: 778 797 779 798 <ul>
Changes to pages/index.in.
10 10 [full-featured SQL|full-featured], [public-domain], 11 11 SQL database engine. 12 12 SQLite is the [most used] database engine in the world. 13 13 <a class="button" href="about.html">More Info</a></p> 14 14 15 15 <hr class="xhr"> 16 16 <span class="hdrfont">Latest Release: </span> 17 -<a href="releaselog/3_20_0.html">Version 3.20.0</a> ([dateof:3.20.0]). 17 +<a href="releaselog/3_21_0.html">Version 3.21.0</a> ([dateof:3.21.0]). 18 18 <a class="button" href="download.html">Download</a> 19 19 <a class="button" href="chronology.html">Prior Releases</a> 20 20 21 21 <div class="mobileonly"> 22 22 <hr class="xhr"> 23 23 <h3>Common Links</h3> 24 24 <tcl>common_links</tcl>
Changes to pages/lang.in.
1622 1622 ^When not in [shared cache mode], 1623 1623 it is possible to have the same database file attached multiple times using 1624 1624 different names, and detaching one connection to a file will leave the 1625 1625 others intact.</p> 1626 1626 ^In [shared cache mode], attempting to attach the same database file more 1627 1627 than once results in an error. 1628 1628 1629 -<p>^This statement will fail if SQLite is in the middle of a transaction.</p> 1630 - 1631 1629 1632 1630 <tcl> 1633 1631 ############################################################################## 1634 1632 Section {DROP INDEX} dropindex {{DROP INDEX}} 1635 1633 1636 1634 RecursiveBubbleDiagram drop-index-stmt 1637 1635 </tcl>
Changes to pages/optoverview.in.
320 320 There are many conditions on this optimization: 321 321 } 322 322 PARAGRAPH { 323 323 <ol> 324 324 <li>^The right-hand side of the LIKE or GLOB must be either a string literal 325 325 or a [parameter] bound to a string literal 326 326 that does not begin with a wildcard character.</li> 327 - <li>^The ESCAPE clause cannot appear on the LIKE operator.</li> 328 327 <li>It must not be possible to make the LIKE or GLOB operator true by 329 328 having a numeric value (instead of a string or blob) on the 330 329 left-hand side. This means that either: 331 330 <ol type="A"> 332 331 <li> the left-hand side of the LIKE or GLOB operator is the name 333 332 of an indexed column with [affinity | TEXT affinity], or</li> 334 333 <li> the right-hand side pattern argument does not begin with a 335 334 minus sign ("-") or a digit.</li> 336 335 </ol> 337 336 This constraint arises from the fact that numbers do not sort in 338 337 lexicographical order. For example: 9<10 but '9'>'10'.</li> 339 338 <li>^The built-in functions used to implement LIKE and GLOB must not 340 - have been overloaded using the sqlite3_create_function() API.</li> 339 + have been overloaded using the [sqlite3_create_function()] API.</li> 341 340 <li>^For the GLOB operator, the column must be indexed using the 342 341 built-in BINARY collating sequence.</li> 343 342 <li>^For the LIKE operator, if [case_sensitive_like] mode is enabled then 344 343 the column must indexed using BINARY collating sequence, or if 345 344 [case_sensitive_like] mode is disabled then the column must indexed 346 345 using built-in NOCASE collating sequence.</li> 346 + <li>If the ESCAPE option is used, the ESCAPE character must be ASCII, 347 + or a single-byte character in UTF-8. 347 348 </ol> 348 349 } 349 350 PARAGRAPH { 350 351 The LIKE operator has two modes that can be set by a 351 352 [case_sensitive_like | pragma]. ^The 352 353 default mode is for LIKE comparisons to be insensitive to differences 353 354 of case for latin1 characters. ^(Thus, by default, the following ................................................................................ 402 403 character then this optimization is attempted. ^If the right-hand side 403 404 is a [parameter] that is bound to a string, then this optimization is 404 405 only attempted if the [prepared statement] containing the expression 405 406 was compiled with [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 406 407 ^The LIKE optimization is not attempted if the 407 408 right-hand side is a [parameter] and the statement was prepared using 408 409 [sqlite3_prepare()] or [sqlite3_prepare16()]. 409 - ^The LIKE optimization is not attempted if there is an ESCAPE phrase 410 - on the LIKE operator. 411 410 } 412 411 PARAGRAPH { 413 412 Suppose the initial sequence of non-wildcard characters on the right-hand 414 413 side of the LIKE or GLOB operator is <i>x</i>. We are using a single 415 414 character to denote this non-wildcard prefix but the reader should 416 415 understand that the prefix can consist of more than 1 character. 417 416 Let <i>y</i> be the smallest string that is the same length as /x/ but which ................................................................................ 1022 1021 started. This results in a slightly faster sort. But the bigger 1023 1022 advantages are that many fewer rows need to be held in memory, 1024 1023 reducing memory requirements, and outputs can begin to appear before 1025 1024 the core query has run to completion. 1026 1025 } 1027 1026 1028 1027 HEADING 1 {Subquery flattening} flattening 1029 -hd_keywords {flattening optimization} 1028 +hd_keywords {flattening optimization} {query flattener} 1030 1029 1031 1030 PARAGRAPH { 1032 1031 When a subquery occurs in the FROM clause of a SELECT, the simplest 1033 1032 behavior is to evaluate the subquery into a transient table, then run 1034 1033 the outer SELECT against the transient table. But such a plan 1035 1034 can be suboptimal since the transient table will not have any indices 1036 1035 and the outer query (which is likely a join) will be forced to do a