mirrors/sqlite
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Small performance optimization in sqlite3WhereBegin().

Browse Source 
FossilOrigin-Name: 39f708d1e286931365a8992dbe7f900108ff1dad146032a284ad1dec09b11e06
This commit is contained in:
drh 2017-08-25 13:34:18 +00:00
parent 6034846eb6
commit 83e8ca54d1
3 changed files with 37 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
manifest
View File

@ -1,5 +1,5 @@
C Convert\sa\sbranch\smade\sunreachable\sby\s[59560d07]\sinto\san\sassert().
D 2017-08-25T13:02:48.882
C Small\sperformance\soptimization\sin\ssqlite3WhereBegin().
D 2017-08-25T13:34:18.937
F Makefile.in c644bbe8ebe4aae82ad6783eae6b6beea4c727b99ff97568b847ced5e2ac7afb
F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
F Makefile.msc 25b154da7f0b3d4924f27378c1f8d006285b80811f1ccf3ed953dbebf6282136
@ -538,7 +538,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
F src/wal.c 839db09792fead5052bb35e533fa485e134913d547d05b5f42e537b73e63f07a
F src/wal.h 8de5d2d3de0956d6f6cb48c83a4012d5f227b8fe940f3a349a4b7e85ebcb492a
F src/walker.c 3ccfa8637f95355bff61144e01a615b8ef26f79c312880848da73f03367da1e6
F src/where.c ad558533d6fe6578857635218633aa241e2428835763c46801be9e68d6ec0701
F src/where.c 0aaa1b085a018c1c2e2da367b48491ce2686aea351bd17772c46b7e04eb51e3d
F src/whereInt.h 93bb90b77d39901eda31b44d8e90da1351193ccfe96876f89b58a93a33b84c3d
F src/wherecode.c e7be3b7f4c11908500cdf02b299d190d3742659533f58e0f4047962fdb5a48da
F src/whereexpr.c fe1fe600d7334e91f3d9d487021362d543fba8ab2f1be5e0d68063d619379c05
@ -1651,7 +1651,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
P e8d23afe8478e42779ec1dd602ca2d77d4f3c26c4d54f52112c5aaa928536538
R c47094d13357cf3081b589cea406d444
P 2738b8db3caa6ce48d27cb5749d27b79241e6f6682b694886f6ef663e5443583
R be107142fb32b5eeca2b38bf38398332
U drh
Z 0c1347313e1f31701f169aeedc1bd394
Z ca59cf9901a72073d38774a5b3f91248

2
manifest.uuid
View File

@ -1 +1 @@
2738b8db3caa6ce48d27cb5749d27b79241e6f6682b694886f6ef663e5443583
39f708d1e286931365a8992dbe7f900108ff1dad146032a284ad1dec09b11e06

59
src/where.c
View File

@ -4537,37 +4537,38 @@ WhereInfo *sqlite3WhereBegin(
if( wctrlFlags & WHERE_WANT_DISTINCT ){
pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
}
}
/* Assign a bit from the bitmask to every term in the FROM clause.
**
** The N-th term of the FROM clause is assigned a bitmask of 1<<N.
**
** The rule of the previous sentence ensures thta if X is the bitmask for
** a table T, then X-1 is the bitmask for all other tables to the left of T.
** Knowing the bitmask for all tables to the left of a left join is
** important. Ticket #3015.
**
** Note that bitmasks are created for all pTabList->nSrc tables in
** pTabList, not just the first nTabList tables. nTabList is normally
** equal to pTabList->nSrc but might be shortened to 1 if the
** WHERE_OR_SUBCLAUSE flag is set.
*/
for(ii=0; ii<pTabList->nSrc; ii++){
createMask(pMaskSet, pTabList->a[ii].iCursor);
sqlite3WhereTabFuncArgs(pParse, &pTabList->a[ii], &pWInfo->sWC);
}
#ifdef SQLITE_DEBUG
{
Bitmask mx = 0;
for(ii=0; ii<pTabList->nSrc; ii++){
Bitmask m = sqlite3WhereGetMask(pMaskSet, pTabList->a[ii].iCursor);
assert( m>=mx );
mx = m;
}else{
/* Assign a bit from the bitmask to every term in the FROM clause.
**
** The N-th term of the FROM clause is assigned a bitmask of 1<<N.
**
** The rule of the previous sentence ensures thta if X is the bitmask for
** a table T, then X-1 is the bitmask for all other tables to the left of T.
** Knowing the bitmask for all tables to the left of a left join is
** important. Ticket #3015.
**
** Note that bitmasks are created for all pTabList->nSrc tables in
** pTabList, not just the first nTabList tables. nTabList is normally
** equal to pTabList->nSrc but might be shortened to 1 if the
** WHERE_OR_SUBCLAUSE flag is set.
*/
ii = 0;
do{
createMask(pMaskSet, pTabList->a[ii].iCursor);
sqlite3WhereTabFuncArgs(pParse, &pTabList->a[ii], &pWInfo->sWC);
}while( (++ii)<pTabList->nSrc );
#ifdef SQLITE_DEBUG
{
Bitmask mx = 0;
for(ii=0; ii<pTabList->nSrc; ii++){
Bitmask m = sqlite3WhereGetMask(pMaskSet, pTabList->a[ii].iCursor);
assert( m>=mx );
mx = m;
}
}
#endif
}
#endif
/* Analyze all of the subexpressions. */
sqlite3WhereExprAnalyze(pTabList, &pWInfo->sWC);
if( db->mallocFailed ) goto whereBeginError;