-C Better\sreporting\sof\swhen\sthe\sWHERE\sclause\sanalysis\sthinks\sthat\san\sindex\nis\scovering.
-D 2022-11-26T20:52:38.117
+C Rework\sthe\scovering\sindex\schecking\sroutine,\swhereIsCoveringIndex(),\sso\sthat\nit\scan\sreturn\sa\s"maybe"\sresult\sfor\saggregate\squeries\swhere\swe\sare\snot\sexactly\nsure.\s\sThe\sindex\sis\sscored\sas\sif\sit\sis\scovering,\sbut\sthe\smain\stable\sis\nstill\sopened.
+D 2022-11-28T15:23:53.775
F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
F src/wal.c b9df133a705093da8977da5eb202eaadb844839f1c7297c08d33471f5491843d
F src/wal.h c3aa7825bfa2fe0d85bef2db94655f99870a285778baa36307c0a16da32b226a
F src/walker.c f890a3298418d7cba3b69b8803594fdc484ea241206a8dfa99db6dd36f8cbb3b
-F src/where.c 1f64631ab2c94b3c11de00ad1d08be9d51ee73acd613c54c4367526f5e2ac241
-F src/whereInt.h df0c79388c0b71b4a91f480d02791679fe0345d40410435c541c8893e95a4d3f
+F src/where.c 81422870d17fdf3880fdb9d3b3965e1aa5efb7a72c6933cec3f1bc8081c463db
+F src/whereInt.h e25203e5bfee149f5f1225ae0166cfb4f1e65490c998a024249e98bb0647377c
F src/wherecode.c 133a94f82858787217d073143617df19e4a6a7d0b771a1519f957608109ad5a5
F src/whereexpr.c 05295b44b54eea76d1ba766f0908928d0e20e990c249344c9521454d3d09c7ae
F src/window.c 14836767adb26573b50f528eb37f8b1336f2c430ab38de7cead1e5c546bb4d8c
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 9ac67ff968e874cf955e46e3993e3215c766feec3d5bdd38d77884eedd86b59e
-R 1dffa8ce2c066e6a4b41c4abd6aac427
+P 17ebcf316b91042c823eea7bb6f1309325023cb5c70538cdb2ce932caee2ef05
+R 254ab4db9b1e239ec16eb2e1a31dc657
U drh
-Z 2a27a64568a31340c97915e2beb3adb7
+Z 489a805b1f3c740affbc27a0febf881c
# Remove this line to create a well-formed Fossil manifest.
assert( pSrc->pTab->szTabRow>0 );
rCostIdx = pNew->nOut + 1 + (15*pProbe->szIdxRow)/pSrc->pTab->szTabRow;
pNew->rRun = sqlite3LogEstAdd(rLogSize, rCostIdx);
- if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK))==0 ){
+ if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK|WHERE_EXPRIDX))==0 ){
pNew->rRun = sqlite3LogEstAdd(pNew->rRun, pNew->nOut + 16);
}
ApplyCostMultiplier(pNew->rRun, pProbe->pTable->costMult);
/*
** Structure passed to the whereIsCoveringIndex Walker callback.
*/
+typedef struct CoveringIndexCheck CoveringIndexCheck;
struct CoveringIndexCheck {
Index *pIdx; /* The index */
int iTabCur; /* Cursor number for the corresponding table */
+ u8 bExpr; /* Uses an indexed expression */
+ u8 bUnidx; /* Uses an unindexed column not within an indexed expr */
};
/*
** matches pExpr, then prune the search.
*/
static int whereIsCoveringIndexWalkCallback(Walker *pWalk, Expr *pExpr){
- int i; /* Loop counter */
- const Index *pIdx; /* The index of interest */
- const i16 *aiColumn; /* Columns contained in the index */
- u16 nColumn; /* Number of columns in the index */
- pIdx = pWalk->u.pCovIdxCk->pIdx;
+ int i; /* Loop counter */
+ const Index *pIdx; /* The index of interest */
+ const i16 *aiColumn; /* Columns contained in the index */
+ u16 nColumn; /* Number of columns in the index */
+ CoveringIndexCheck *pCk; /* Info about this search */
+
+ pCk = pWalk->u.pCovIdxCk;
+ pIdx = pCk->pIdx;
if( (pExpr->op==TK_COLUMN || pExpr->op==TK_AGG_COLUMN) ){
/* if( pExpr->iColumn<(BMS-1) && pIdx->bHasExpr==0 ) return WRC_Continue;*/
- if( pExpr->iTable!=pWalk->u.pCovIdxCk->iTabCur ) return WRC_Continue;
+ if( pExpr->iTable!=pCk->iTabCur ) return WRC_Continue;
pIdx = pWalk->u.pCovIdxCk->pIdx;
aiColumn = pIdx->aiColumn;
nColumn = pIdx->nColumn;
for(i=0; i<nColumn; i++){
if( aiColumn[i]==pExpr->iColumn ) return WRC_Continue;
}
- pWalk->eCode = 1;
+ pCk->bUnidx = 1;
return WRC_Abort;
}else if( pIdx->bHasExpr
&& exprIsCoveredByIndex(pExpr, pIdx, pWalk->u.pCovIdxCk->iTabCur) ){
+ pCk->bExpr = 1;
return WRC_Prune;
}
return WRC_Continue;
/*
** pIdx is an index that covers all of the low-number columns used by
-** pWInfo->pSelect (columns from 0 through 62). But there are columns
-** in pWInfo->pSelect beyond 62. This routine tries to answer the question
-** of whether pIdx covers *all* columns in the query.
+** pWInfo->pSelect (columns from 0 through 62) or an index that has
+** expressions terms. Hence, we cannot determine whether or not it is
+** a covering index by using the colUsed bitmasks. We have to do a search
+** to see if the index is covering. This routine does that search.
+**
+** The return value is one of these:
+**
+** 0 The index is definitely not a covering index
**
-** Return 0 if pIdx is a covering index. Return non-zero if pIdx is
-** not a covering index or if we are unable to determine if pIdx is a
-** covering index.
+** WHERE_IDX_ONLY The index is definitely a covering index
**
-** This routine is an optimization. It is always safe to return non-zero.
-** But returning zero when non-zero should have been returned can lead to
-** incorrect bytecode and assertion faults.
+** WHERE_EXPRIDX The index is likely a covering index, but it is
+** difficult to determine precisely because of the
+** expressions that are indexed. Score it as a
+** covering index, but still keep the main table open
+** just in case we need it.
+**
+** This routine is an optimization. It is always safe to return zero.
+** But returning one of the other two values when zero should have been
+** returned can lead to incorrect bytecode and assertion faults.
*/
static SQLITE_NOINLINE u32 whereIsCoveringIndex(
WhereInfo *pWInfo, /* The WHERE clause context */
Index *pIdx, /* Index that is being tested */
int iTabCur /* Cursor for the table being indexed */
){
- int i;
+ int i, rc;
struct CoveringIndexCheck ck;
Walker w;
if( pWInfo->pSelect==0 ){
/* We don't have access to the full query, so we cannot check to see
** if pIdx is covering. Assume it is not. */
- return 1;
+ return 0;
}
if( pIdx->bHasExpr==0 ){
for(i=0; i<pIdx->nColumn; i++){
/* pIdx does not index any columns greater than 62, but we know from
** colMask that columns greater than 62 are used, so this is not a
** covering index */
- return 1;
+ return 0;
}
}
ck.pIdx = pIdx;
ck.iTabCur = iTabCur;
+ ck.bExpr = 0;
+ ck.bUnidx = 0;
memset(&w, 0, sizeof(w));
w.xExprCallback = whereIsCoveringIndexWalkCallback;
w.xSelectCallback = sqlite3SelectWalkNoop;
w.u.pCovIdxCk = &ck;
- w.eCode = 0;
sqlite3WalkSelect(&w, pWInfo->pSelect);
- return w.eCode;
+ if( ck.bUnidx ){
+ rc = 0;
+ }else if( ck.bExpr ){
+ rc = WHERE_EXPRIDX;
+ }else{
+ rc = WHERE_IDX_ONLY;
+ }
+ return rc;
}
/*
}else{
Bitmask m;
if( pProbe->isCovering ){
- pNew->wsFlags = WHERE_IDX_ONLY | WHERE_INDEXED;
m = 0;
+ pNew->wsFlags = WHERE_IDX_ONLY | WHERE_INDEXED;
}else{
m = pSrc->colUsed & pProbe->colNotIdxed;
- if( m==TOPBIT || (pProbe->bHasExpr && !pProbe->bHasVCol) ){
- m = whereIsCoveringIndex(pWInfo, pProbe, pSrc->iCursor);
- WHERETRACE(0xff,
- ("-> %s %s a covering index according to whereIsCoveringIndex()\n",
- pProbe->zName, m==0 ? "is" : "is not"));
- }else{
+ pNew->wsFlags = WHERE_INDEXED;
+ if( m==TOPBIT || (pProbe->bHasExpr && !pProbe->bHasVCol && m!=0) ){
+ u32 isCov = whereIsCoveringIndex(pWInfo, pProbe, pSrc->iCursor);
+ if( isCov==0 ){
+ WHERETRACE(0xff,
+ ("-> %s is not a covering index"
+ " according to whereIsCoveringIndex()\n", pProbe->zName));
+ assert( m!=0 );
+ }else{
+ m = 0;
+ pNew->wsFlags |= isCov;
+ if( isCov & WHERE_IDX_ONLY ){
+ WHERETRACE(0xff,
+ ("-> %s is a covering expression index"
+ " according to whereIsCoveringIndex()\n", pProbe->zName));
+ }else{
+ assert( isCov==WHERE_EXPRIDX );
+ WHERETRACE(0xff,
+ ("-> %s might be a covering expression index"
+ " according to whereIsCoveringIndex()\n", pProbe->zName));
+ }
+ }
+ }else if( m==0 ){
WHERETRACE(0xff,
- ("-> %s %s a covering index according to bitmasks\n",
+ ("-> %s a covering index according to bitmasks\n",
pProbe->zName, m==0 ? "is" : "is not"));
+ pNew->wsFlags = WHERE_IDX_ONLY | WHERE_INDEXED;
}
- pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED;
}
/* Full scan via index */
projects / thirdparty / sqlite.git / commitdiff
