Experimental changes that try to identify indexes as covering when they contain
expressions which do cover all data uses. This check-in does not work, because
the AggInfo object might still refer to individual columns. The purpose of
this check-in is to preserve the idea. I might come back to it later.
FossilOrigin-Name: 018914a5a1dbf09307db3f85627f136fa011ab58641796471f5700937bd69bb6
diff --git a/manifest b/manifest
index 2443057..e015f63 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Minor\sbuild\scleanups\sand\sfix\sa\sharmless\srace\scondition\sin\sthe\sOPFS\spart\sof\stester1.js.
-D 2022-11-02T14:08:59.340
+C Experimental\schanges\sthat\stry\sto\sidentify\sindexes\sas\scovering\swhen\sthey\scontain\nexpressions\swhich\sdo\scover\sall\sdata\suses.\s\sThis\scheck-in\sdoes\snot\swork,\sbecause\nthe\sAggInfo\sobject\smight\sstill\srefer\sto\sindividual\scolumns.\s\sThe\spurpose\sof\nthis\scheck-in\sis\sto\spreserve\sthe\sidea.\s\sI\smight\scome\sback\sto\sit\slater.
+D 2022-11-03T21:08:56.993
F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -723,7 +723,7 @@
F src/wal.c b9df133a705093da8977da5eb202eaadb844839f1c7297c08d33471f5491843d
F src/wal.h c3aa7825bfa2fe0d85bef2db94655f99870a285778baa36307c0a16da32b226a
F src/walker.c f890a3298418d7cba3b69b8803594fdc484ea241206a8dfa99db6dd36f8cbb3b
-F src/where.c 1ef5aae7fac877057b9f360f06b26d4275888460d8fb6e92bbb9e70e07afe946
+F src/where.c 5188da8bcc2fd5988d64c37eb69e0a0ae44d4b9798c4c7d31074434961f907a6
F src/whereInt.h df0c79388c0b71b4a91f480d02791679fe0345d40410435c541c8893e95a4d3f
F src/wherecode.c 133a94f82858787217d073143617df19e4a6a7d0b771a1519f957608109ad5a5
F src/whereexpr.c 05295b44b54eea76d1ba766f0908928d0e20e990c249344c9521454d3d09c7ae
@@ -2054,8 +2054,11 @@
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P f6fa0cffa921ccde8910e7fa4a63c2e4ef8ddb376c8ce99e436b27ac332c4498
-R 49cc6fc37416a3ba7fdfd0b20ce15895
-U stephan
-Z b66cc4ccdf23cf485ede2fda7e429a86
+P 70ee6ee014bc4e2c1daa9b4a8909cf76ccecf32de1eb39055f20d3d0b1daa1bd
+R 1dc6261e5b309b19594c2d2789301577
+T *branch * indexed-expr-exp
+T *sym-indexed-expr-exp *
+T -sym-trunk *
+U drh
+Z 39e597a6456d4496ffa146482c09b77b
# Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index f545a72..64c1e62 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-70ee6ee014bc4e2c1daa9b4a8909cf76ccecf32de1eb39055f20d3d0b1daa1bd
\ No newline at end of file
+018914a5a1dbf09307db3f85627f136fa011ab58641796471f5700937bd69bb6
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index 7ba72d2..8991b5b 100644
--- a/src/where.c
+++ b/src/where.c
@@ -3274,29 +3274,51 @@
const Index *pIdx; /* The index of interest */
const i16 *aiColumn; /* Columns contained in the index */
u16 nColumn; /* Number of columns in the index */
- if( pExpr->op!=TK_COLUMN && pExpr->op!=TK_AGG_COLUMN ) return WRC_Continue;
- if( pExpr->iColumn<(BMS-1) ) return WRC_Continue;
- if( pExpr->iTable!=pWalk->u.pCovIdxCk->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;
+ if( pExpr->op==TK_COLUMN || pExpr->op==TK_AGG_COLUMN ){
+ if( pExpr->iTable!=pWalk->u.pCovIdxCk->iTabCur ){
+ return WRC_Prune;
+ }
+ pIdx = pWalk->u.pCovIdxCk->pIdx;
+ aiColumn = pIdx->aiColumn;
+ nColumn = pIdx->nColumn;
+ for(i=0; i<nColumn; i++){
+ if( aiColumn[i]==pExpr->iColumn ){
+ return WRC_Prune;
+ }
+ }
+ pWalk->eCode = 0; /* Not a covering index */
+ return WRC_Abort;
+ }else if( pWalk->eCode==2 ){
+ int iCur = pWalk->u.pCovIdxCk->iTabCur;
+ pIdx = pWalk->u.pCovIdxCk->pIdx;
+ assert( pIdx->aColExpr!=0 );
+ aiColumn = pIdx->aiColumn;
+ nColumn = pIdx->nColumn;
+ for(i=0; i<nColumn; i++){
+ if( aiColumn[i]==XN_EXPR
+ && sqlite3ExprCompare(0, pExpr, pIdx->aColExpr->a[i].pExpr, iCur)==0
+ ){
+ return WRC_Prune;
+ }
+ }
}
- pWalk->eCode = 1;
- return WRC_Abort;
+ 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.
+** pIdx is an index for which we cannot determine is covering using
+** the SrcItem.colUsed bitmask. We can't use colUsed to make the
+** determination for either of these reasons:
**
-** 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.
+** * pIdx might contains indexed expressions.
+** * SrcItem.colUsed indicates that columns beyond the 63rd column
+** are used in the query, making bitmap tests ineffective.
+**
+** This routine does extra work to try to make a more accurate determination
+** of whether or not pIdx is covering. Return 0 if we know that pIdx is
+** covering. Return non-zero if pIdx is not covering or if unable to
+** complete the analysis.
**
** 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
@@ -3310,18 +3332,20 @@
int i;
struct CoveringIndexCheck ck;
Walker w;
+ int bHasHigh = 0;
+ int bHasExpr = 0;
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;
}
for(i=0; i<pIdx->nColumn; i++){
- if( pIdx->aiColumn[i]>=BMS-1 ) break;
+ if( pIdx->aiColumn[i]>=BMS-1 ) bHasHigh = 1;
+ if( pIdx->aiColumn[i]==XN_EXPR ) bHasExpr = 1;
}
- if( i>=pIdx->nColumn ){
- /* 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 */
+ if( bHasHigh==0 && bHasExpr==0 ){
+ /* pIdx does not index any columns greater than 62 nor any expression
+ ** columns. The colMask analysis must have been correct. Not covering. */
return 1;
}
ck.pIdx = pIdx;
@@ -3330,9 +3354,9 @@
w.xExprCallback = whereIsCoveringIndexWalkCallback;
w.xSelectCallback = sqlite3SelectWalkNoop;
w.u.pCovIdxCk = &ck;
- w.eCode = 0;
+ w.eCode = 1 + bHasExpr;
sqlite3WalkSelect(&w, pWInfo->pSelect);
- return w.eCode;
+ return w.eCode==0;
}
/*
@@ -3552,7 +3576,7 @@
m = 0;
}else{
m = pSrc->colUsed & pProbe->colNotIdxed;
- if( m==TOPBIT ){
+ if( m==TOPBIT || (pProbe->bHasExpr && m!=0) ){
m = whereIsCoveringIndex(pWInfo, pProbe, pSrc->iCursor);
}
pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED;