-C Fix\sa\smissed\soptimization\sopportunity\sdue\sto\sa\stypo\sin\scheck-in\s[898bfa1afd8260ea].\nReported\sby\s[forum:/forumpost/2026-01-31T00:49:53z|forum\spost\s2026-01-31T00:49:53z].
-D 2026-01-31T02:17:55.945
+C An\sexperimental\squery-planner\schange\sthat\sreduces\sthe\sestimated\snumber\nof\soutput\srows\sfor\sFROM\sclause\sterms\sthat\sare\srestricted\sby\sa\sLIKE\sor\nGLOB\soperator,\sbased\son\sthe\snumber\sof\sbytes\sin\sthe\spattern.\s\sThe\sidea\sis\nthat\slonger\spatterns\swill\smatch\sfewer\srecords\sand\shence\sshould\sreduce\sthe\nestimated\soutput\scount.\s\sThe\simplementation\sis\snot\sworkable\sas\sit\sstands\nnow.\s\sThis\sis\sjust\sa\scrazy\sidea,\ssaved\sfor\sfuture\sreference.
+D 2026-02-01T00:37:04.751
F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
F src/expr.c 1ca95a1f8d0ef5113ca948ffac815183e30d754403f871e91d9ebb94ec92ee0d
F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
F src/fkey.c c065da737307a29e4d240ac727758dbf4102cb3218a1f651eb689b6a6fa12531
-F src/func.c efbcfe7cb7fc92fe5299c9aaa141075eb60d2108253e99bc235384ed6a90d937
+F src/func.c 315b9e6451f8d2456e4aabc919b5e74b81e8bb1c184df5824a8cc28742fe8746
F src/global.c a19e4b1ca1335f560e9560e590fc13081e21f670643367f99cb9e8f9dc7d615b
F src/hash.c 03c8c0f4be9e8bcb6de65aa26d34a61d48a9430747084a69f9469fbb00ea52ca
F src/hash.h 46b92795a95bfefb210f52f0c316e9d7cdbcdd7e7fcfb0d8be796d3a5767cddf
F src/sqlite.h.in 8bcbaecfe2cbecf8c5c1381354fcdd7d307443e88b4953fccb222456c1267b61
F src/sqlite3.rc 015537e6ac1eec6c7050e17b616c2ffe6f70fca241835a84a4f0d5937383c479
F src/sqlite3ext.h 1b7a0ee438bb5c2896d0609c537e917d8057b3340f6ad004d2de44f03e3d3cca
-F src/sqliteInt.h f4b50f8c287b858bb23dd51daee29ff424697be9a0753cf37df98fbe1806125b
+F src/sqliteInt.h f3005a643c484e89a4836773c10f3225ac6153910ec00d18026c6e7c05cac331
F src/sqliteLimit.h 904a3f520362c7065c18165aaabd504fb13cc1b76cb411f38bd41ac219e4af1e
F src/status.c 7565d63a79aa2f326339a24a0461a60096d0bd2bce711fefb50b5c89335f3592
F src/table.c 0f141b58a16de7e2fbe81c308379e7279f4c6b50eb08efeec5892794a0ba30d1
F src/wal.c 505a98fbc599a971d92cb90371cf54546c404cd61e04fd093e7b0c8ff978f9b6
F src/wal.h ba252daaa94f889f4b2c17c027e823d9be47ce39da1d3799886bbd51f0490452
F src/walker.c d5006d6b005e4ea7302ad390957a8d41ed83faa177e412f89bc5600a7462a014
-F src/where.c 4992c31e356b185a71bb3e9fc1ac6d747864240d5da4e81ec39b7ab38706332e
+F src/where.c 3ad5ed6958610deaacda7e0b7add8e9844fab10c3f36f31178e69476dbbdd531
F src/whereInt.h 8d94cb116c9e06205c3d5ac87af065fc044f8cf08bfdccd94b6ea1c1308e65da
F src/wherecode.c 71c5c6804b7f882dec8ec858758accae02fcfca13df3cc720f1f258e663ec7c5
F src/whereexpr.c cadb37fbaa2cb6d1ec1687923c3ac21aed4187d198f4500c00a01abb24c3cb44
F tool/warnings.sh d924598cf2f55a4ecbc2aeb055c10bd5f48114793e7ba25f9585435da29e7e98
F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
F tool/winmain.c 00c8fb88e365c9017db14c73d3c78af62194d9644feaf60e220ab0f411f3604c
-P d294106ecb78d765305ab740007f4a678e28baa13ae403fe57ea9cbfc259620f
-R 464b9c781876348fa88209b9bcbdb4fe
+P 3a4f9a323da90611d7eda51b90cb058175ddde0a128e1ff00ce58cc83af0f376
+R c8f080e13db002ac2d0b968aded30d67
+T *branch * prune-by-like-glob
+T *sym-prune-by-like-glob *
+T -sym-trunk *
U drh
-Z fade084440f5178d675ec00dcd7ba976
+Z 578e4e749f8bb7df2b1ce02458c08702
# Remove this line to create a well-formed Fossil manifest.
-branch trunk
-tag trunk
+branch prune-by-like-glob
+tag prune-by-like-glob
-3a4f9a323da90611d7eda51b90cb058175ddde0a128e1ff00ce58cc83af0f376
+97bcb56a208af0687750a6438981bbfe36a8d516d996178e62551d302ef811ee
}
/*
-** pExpr points to an expression which implements a function. If
-** it is appropriate to apply the LIKE optimization to that function
+** Callback for sqlite3ExprStrlenEst().
+**
+** If this node is a string literal that is longer pWalker->sz, then set
+** pWalker->sz to the byte length of that string literal.
+*/
+static int exprNodeStrlenEst(Walker *pWalker, Expr *pExpr){
+ if( pExpr->op==TK_STRING ){
+ int sz = sqlite3Strlen30(pExpr->u.zToken);
+ if( sz>pWalker->u.sz ) pWalker->u.sz = sz;
+ }
+ return WRC_Continue;
+}
+
+/*
+** Return the length of the longest string literal in the given
+** expression.
+*/
+int sqlite3ExprStrlenEst(Expr *p){
+ Walker w;
+ w.u.sz = 0;
+ w.xExprCallback = exprNodeStrlenEst;
+ w.xSelectCallback = sqlite3SelectWalkFail;
+#ifdef SQLITE_DEBUG
+ w.xSelectCallback2 = sqlite3SelectWalkAssert2;
+#endif
+ sqlite3WalkExpr(&w, p);
+ return w.u.sz;
+}
+
+/*
+** pExpr points to an expression which implements a function.
+** If pExpr is anything other than a LIKE or GLOB operator, return
+** false (0) and skip all the rest.
+**
+** There are two cases.
+**
+** Case 1: pIsNocase and aWc are both non-NULL
+**
+** If it is appropriate to apply the LIKE optimization to that function
** then set aWc[0] through aWc[2] to the wildcard characters and the
** escape character and then return TRUE. If the function is not a
** LIKE-style function then return FALSE.
** the function (default for LIKE). If the function makes the distinction
** between uppercase and lowercase (as does GLOB) then *pIsNocase is set to
** false.
+**
+** Case 2: pIsNocase and aWc are both NULL
+**
+** Return the estimated length of the pattern. Zero is a possible return
+** value in this case.
*/
int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocase, char *aWc){
FuncDef *pDef;
int nExpr;
+ assert( (aWc==0)==(pIsNocase==0) );
assert( pExpr!=0 );
assert( pExpr->op==TK_FUNCTION );
assert( ExprUseXList(pExpr) );
return 0;
}
- /* The memcpy() statement assumes that the wildcard characters are
- ** the first three statements in the compareInfo structure. The
- ** asserts() that follow verify that assumption
- */
- memcpy(aWc, pDef->pUserData, 3);
- assert( (char*)&likeInfoAlt == (char*)&likeInfoAlt.matchAll );
- assert( &((char*)&likeInfoAlt)[1] == (char*)&likeInfoAlt.matchOne );
- assert( &((char*)&likeInfoAlt)[2] == (char*)&likeInfoAlt.matchSet );
-
- if( nExpr<3 ){
- aWc[3] = 0;
+ if( aWc!=0 ){
+ /* The memcpy() statement assumes that the wildcard characters are
+ ** the first three statements in the compareInfo structure. The
+ ** asserts() that follow verify that assumption
+ */
+ memcpy(aWc, pDef->pUserData, 3);
+ assert( (char*)&likeInfoAlt == (char*)&likeInfoAlt.matchAll );
+ assert( &((char*)&likeInfoAlt)[1] == (char*)&likeInfoAlt.matchOne );
+ assert( &((char*)&likeInfoAlt)[2] == (char*)&likeInfoAlt.matchSet );
+
+ if( nExpr<3 ){
+ aWc[3] = 0;
+ }else{
+ Expr *pEscape = pExpr->x.pList->a[2].pExpr;
+ char *zEscape;
+ if( pEscape->op!=TK_STRING ) return 0;
+ assert( !ExprHasProperty(pEscape, EP_IntValue) );
+ zEscape = pEscape->u.zToken;
+ if( zEscape[0]==0 || zEscape[1]!=0 ) return 0;
+ if( zEscape[0]==aWc[0] ) return 0;
+ if( zEscape[0]==aWc[1] ) return 0;
+ aWc[3] = zEscape[0];
+ }
+ *pIsNocase = (pDef->funcFlags & SQLITE_FUNC_CASE)==0;
+ return 1;
}else{
- Expr *pEscape = pExpr->x.pList->a[2].pExpr;
- char *zEscape;
- if( pEscape->op!=TK_STRING ) return 0;
- assert( !ExprHasProperty(pEscape, EP_IntValue) );
- zEscape = pEscape->u.zToken;
- if( zEscape[0]==0 || zEscape[1]!=0 ) return 0;
- if( zEscape[0]==aWc[0] ) return 0;
- if( zEscape[0]==aWc[1] ) return 0;
- aWc[3] = zEscape[0];
- }
-
- *pIsNocase = (pDef->funcFlags & SQLITE_FUNC_CASE)==0;
- return 1;
+ return sqlite3ExprStrlenEst(pExpr->x.pList->a[0].pExpr);
+ }
}
/* Mathematical Constants */
NameContext *pNC; /* Naming context */
int n; /* A counter */
int iCur; /* A cursor number */
+ int sz; /* String literal length */
SrcList *pSrcList; /* FROM clause */
struct CCurHint *pCCurHint; /* Used by codeCursorHint() */
struct RefSrcList *pRefSrcList; /* sqlite3ReferencesSrcList() */
void sqlite3DefaultRowEst(Index*);
void sqlite3RegisterLikeFunctions(sqlite3*, int);
int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
+int sqlite3ExprStrlenEst(Expr*);
void sqlite3SchemaClear(void *);
Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
** "x" column is boolean or else -1 or 0 or 1 is a common default value
** on the "x" column and so in that case only cap the output row estimate
** at 1/2 instead of 1/4.
+**
+** Heuristic 3: If there is a LIKE or GLOB operator with a large
+** constant pattern, then reduce the size of the search space according
+** to the length of the pattern, under the theory that longer patterns
+** are less likely to match.
*/
static void whereLoopOutputAdjust(
WhereClause *pWC, /* The WHERE clause */
pTerm->wtFlags |= TERM_HEURTRUTH;
iReduce = k;
}
+ }else
+ if( pTerm->pExpr->op==TK_FUNCTION ){
+ int szPattern;
+ Expr *pExpr = pTerm->pExpr;
+ sqlite3 *db = pWC->pWInfo->pParse->db;
+ szPattern = sqlite3IsLikeFunction(db, pExpr, 0, 0);
+ if( szPattern>3 ){
+ pLoop->nOut -= szPattern*3-6;
+ }
}
}
}
projects / thirdparty / sqlite.git / commitdiff
