From: drh Date: Tue, 20 Sep 2005 08:47:20 +0000 (+0000) Subject: Update comments in where.c. No code changes. (CVS 2727) X-Git-Tag: version-3.6.10~3433 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b6fb62d9b46f0ad3c8eab3169b50d4ef313eff77;p=thirdparty%2Fsqlite.git Update comments in where.c. No code changes. (CVS 2727) FossilOrigin-Name: bb84d27eda64479d65b13fbbcaeef6a00da4d103 --- diff --git a/manifest b/manifest index 4639da52b6..a40d4df06d 100644 --- a/manifest +++ b/manifest @@ -1,5 +1,5 @@ -C Documentation\supdates.\s(CVS\s2726) -D 2005-09-20T01:36:30 +C Update\scomments\sin\swhere.c.\s\sNo\scode\schanges.\s(CVS\s2727) +D 2005-09-20T08:47:20 F Makefile.in 12784cdce5ffc8dfb707300c34e4f1eb3b8a14f1 F Makefile.linux-gcc 06be33b2a9ad4f005a5f42b22c4a19dab3cbb5c7 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028 @@ -87,7 +87,7 @@ F src/vdbeapi.c 85bbe1d0243a89655433d60711b4bd71979b59cd F src/vdbeaux.c 57a6ced8417bdc6f06c391d9c560ecbbed644ef3 F src/vdbefifo.c 9efb94c8c3f4c979ebd0028219483f88e57584f5 F src/vdbemem.c fea0744936008831daa17cdc75056c3ca1469690 -F src/where.c 2b7b4dd112a027021d9c53e25d221761d572a925 +F src/where.c 363b4fb0aee9fe69367ceaab0974dafa4e4ab900 F tclinstaller.tcl 046e3624671962dc50f0481d7c25b38ef803eb42 F test/all.test 7f0988442ab811dfa41793b5b550f5828ce316f3 F test/alter.test 9d6837a3d946b73df692b7cef2a7644d2e2f6bc6 @@ -311,7 +311,7 @@ F www/tclsqlite.tcl ddcf912ea48695603c8ed7efb29f0812ef8d1b49 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0 F www/version3.tcl a99cf5f6d8bd4d5537584a2b342f0fb9fa601d8b F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513 -P ea10f9785e3c5248dafcc297f3a2c5465b6e0dba -R 6ad171a801eb8b84ac88c34ad2f04d27 +P 6ec8883c366532948e619830ff7d9f63b79fc08b +R 83e2318d245416067a9bf94d66214656 U drh -Z 23a34f97623654d558cd9b041aa96deb +Z 7b8f65438258711df695628d2834385c diff --git a/manifest.uuid b/manifest.uuid index b08c638236..d9df85d246 100644 --- a/manifest.uuid +++ b/manifest.uuid @@ -1 +1 @@ -6ec8883c366532948e619830ff7d9f63b79fc08b \ No newline at end of file +bb84d27eda64479d65b13fbbcaeef6a00da4d103 \ No newline at end of file diff --git a/src/where.c b/src/where.c index a32f5c76df..d9ddef026c 100644 --- a/src/where.c +++ b/src/where.c @@ -16,7 +16,7 @@ ** so is applicable. Because this module is responsible for selecting ** indices, you might also think of this module as the "query optimizer". ** -** $Id: where.c,v 1.177 2005/09/19 21:05:49 drh Exp $ +** $Id: where.c,v 1.178 2005/09/20 08:47:20 drh Exp $ */ #include "sqliteInt.h" @@ -232,7 +232,7 @@ static int whereClauseInsert(WhereClause *pWC, Expr *p, int flags){ /* ** This routine identifies subexpressions in the WHERE clause where -** each subexpression is separate by the AND operator or some other +** each subexpression is separated by the AND operator or some other ** operator specified in the op parameter. The WhereClause structure ** is filled with pointers to subexpressions. For example: ** @@ -281,7 +281,7 @@ static Bitmask getMask(ExprMaskSet *pMaskSet, int iCursor){ ** ** There is one cursor per table in the FROM clause. The number of ** tables in the FROM clause is limited by a test early in the -** sqlite3WhereBegin() routien. So we know that the pMaskSet->ix[] +** sqlite3WhereBegin() routine. So we know that the pMaskSet->ix[] ** array will never overflow. */ static void createMask(ExprMaskSet *pMaskSet, int iCursor){ @@ -532,7 +532,7 @@ static int isLikeOrGlob( ** to the standard form of "X ". If the expression is of ** the form "X Y" where both X and Y are columns, then the original ** expression is unchanged and a new virtual expression of the form -** "Y X" is added to the WHERE clause. +** "Y X" is added to the WHERE clause and analyzed separately. */ static void exprAnalyze( SrcList *pSrc, /* the FROM clause */ @@ -847,7 +847,7 @@ static int sortableByRowid( } /* -** Prepare a crude estimate of the logorithm of the input value. +** Prepare a crude estimate of the logarithm of the input value. ** The results need not be exact. This is only used for estimating ** the total cost of performing operatings with O(logN) or O(NlogN) ** complexity. Because N is just a guess, it is no great tragedy if @@ -1106,11 +1106,12 @@ static double bestIndex( ** of a LEFT OUTER JOIN. In (1), the term is not disabled. ** ** Disabling a term causes that term to not be tested in the inner loop -** of the join. Disabling is an optimization. We would get the correct -** results if nothing were ever disabled, but joins might run a little -** slower. The trick is to disable as much as we can without disabling -** too much. If we disabled in (1), we'd get the wrong answer. -** See ticket #813. +** of the join. Disabling is an optimization. When terms are satisfied +** by indices, we disable them to prevent redundant tests in the inner +** loop. We would get the correct results if nothing were ever disabled, +** but joins might run a little slower. The trick is to disable as much +** as we can without disabling too much. If we disabled in (1), we'd get +** the wrong answer. See ticket #813. */ static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){ if( pTerm @@ -1425,7 +1426,7 @@ WhereInfo *sqlite3WhereBegin( /* Analyze all of the subexpressions. Note that exprAnalyze() might ** add new virtual terms onto the end of the WHERE clause. We do not ** want to analyze these virtual terms, so start analyzing at the end - ** and work forward so that they added virtual terms are never processed. + ** and work forward so that the added virtual terms are never processed. */ for(i=0; inSrc; i++){ createMask(&maskSet, pTabList->a[i].iCursor);