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Cache and reuse virtual table index information in the optimizer.

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Improved diagnostics for virtual table index selection. (CVS 3300)

FossilOrigin-Name: 28413cf2b3f0e6f294e1f3c59fcce135b65c294f
This commit is contained in:
drh
2006-06-27 01:54:26 +00:00
parent c1be632489
commit 6d209d8b0d
4 changed files with 101 additions and 37 deletions
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98
src/where.c
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@@ -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 1.223 2006/06/24 11:51:35 danielk1977 Exp $
** $Id: where.c,v 1.224 2006/06/27 01:54:26 drh Exp $
*/
#include "sqliteInt.h"
@@ -949,6 +949,51 @@ static double estLog(double N){
return logN;
}
/*
** Two routines for printing the content of an sqlite3_index_info
** structure. Used for testing and debugging only. If neither
** SQLITE_TEST or SQLITE_DEBUG are defined, then these routines
** are no-ops.
*/
#if !defined(SQLITE_OMIT_VIRTUALTABLE) && \
(defined(SQLITE_TEST) || defined(SQLITE_DEBUG))
static void TRACE_IDX_INPUTS(sqlite3_index_info *p){
int i;
if( !sqlite3_where_trace ) return;
for(i=0; i<p->nConstraint; i++){
sqlite3DebugPrintf(" constraint[%d]: col=%d termid=%d op=%d usabled=%d\n",
i,
p->aConstraint[i].iColumn,
p->aConstraint[i].iTermOffset,
p->aConstraint[i].op,
p->aConstraint[i].usable);
}
for(i=0; i<p->nOrderBy; i++){
sqlite3DebugPrintf(" orderby[%d]: col=%d desc=%d\n",
i,
p->aOrderBy[i].iColumn,
p->aOrderBy[i].desc);
}
}
static void TRACE_IDX_OUTPUTS(sqlite3_index_info *p){
int i;
if( !sqlite3_where_trace ) return;
for(i=0; i<p->nConstraint; i++){
sqlite3DebugPrintf(" usage[%d]: argvIdx=%d omit=%d\n",
i,
p->aConstraintUsage[i].argvIndex,
p->aConstraintUsage[i].omit);
}
sqlite3DebugPrintf(" idxNum=%d\n", p->idxNum);
sqlite3DebugPrintf(" idxStr=%s\n", p->idxStr);
sqlite3DebugPrintf(" orderByConsumed=%d\n", p->orderByConsumed);
sqlite3DebugPrintf(" estimatedCost=%g\n", p->estimatedCost);
}
#else
#define TRACE_IDX_INPUTS(A)
#define TRACE_IDX_OUTPUTS(A)
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Compute the best index for a virtual table.
@@ -993,6 +1038,7 @@ static double bestVirtualIndex(
if( pIdxInfo==0 ){
WhereTerm *pTerm;
int nTerm;
TRACE(("Recomputing index info for %s...\n", pTab->zName));
/* Count the number of possible WHERE clause constraints referring
** to this virtual table */
@@ -1125,7 +1171,10 @@ static double bestVirtualIndex(
}
sqlite3SafetyOff(pParse->db);
TRACE(("xBestIndex for %s\n", pTab->zName));
TRACE_IDX_INPUTS(pIdxInfo);
rc = pTab->pVtab->pModule->xBestIndex(pTab->pVtab, pIdxInfo);
TRACE_IDX_OUTPUTS(pIdxInfo);
if( rc!=SQLITE_OK ){
if( rc==SQLITE_NOMEM ){
sqlite3FailedMalloc();
@@ -1136,7 +1185,6 @@ static double bestVirtualIndex(
}else{
rc = sqlite3SafetyOn(pParse->db);
}
*(int*)&pIdxInfo->nOrderBy = nOrderBy;
return pIdxInfo->estimatedCost;
}
@@ -1792,8 +1840,7 @@ WhereInfo *sqlite3WhereBegin(
int bestJ = 0; /* The value of j */
Bitmask m; /* Bitmask value for j or bestJ */
int once = 0; /* True when first table is seen */
sqlite3_index_info *pBestIndex = 0;
sqlite3_index_info *pIndex = 0;
sqlite3_index_info *pIndex; /* Current virtual index */
lowestCost = SQLITE_BIG_DBL;
for(j=iFrom, pTabItem=&pTabList->a[j]; j<pTabList->nSrc; j++, pTabItem++){
@@ -1809,11 +1856,14 @@ WhereInfo *sqlite3WhereBegin(
}
assert( pTabItem->pTab );
#ifndef SQLITE_OMIT_VIRTUALTABLE
pIndex = 0;
if( IsVirtual(pTabItem->pTab) ){
sqlite3_index_info **ppIdxInfo = &pWInfo->a[j].pIdxInfo;
cost = bestVirtualIndex(pParse, &wc, pTabItem, notReady,
ppOrderBy ? *ppOrderBy : 0, i==0,
&pIndex);
ppIdxInfo);
flags = WHERE_VIRTUALTABLE;
pIndex = *ppIdxInfo;
if( pIndex && pIndex->orderByConsumed ){
flags = WHERE_VIRTUALTABLE | WHERE_ORDERBY;
}
@@ -1834,12 +1884,7 @@ WhereInfo *sqlite3WhereBegin(
bestNEq = nEq;
bestJ = j;
#ifndef SQLITE_OMIT_VIRTUALTABLE
sqliteFree(pBestIndex);
pBestIndex = pIndex;
pIndex = 0;
}else{
sqliteFree(pIndex);
pIndex = 0;
pLevel->pBestIdx = pIndex;
#endif
}
if( doNotReorder ) break;
@@ -1855,7 +1900,6 @@ WhereInfo *sqlite3WhereBegin(
pLevel->nEq = bestNEq;
pLevel->aInLoop = 0;
pLevel->nIn = 0;
pLevel->pIdxInfo = pBestIndex;
if( pBest ){
pLevel->iIdxCur = pParse->nTab++;
}else{
@@ -1898,10 +1942,10 @@ WhereInfo *sqlite3WhereBegin(
zMsg = sqlite3MPrintf("%z USING PRIMARY KEY", zMsg);
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
else if( pLevel->pIdxInfo ){
sqlite3_index_info *pIdxInfo = pLevel->pIdxInfo;
else if( pLevel->pBestIdx ){
sqlite3_index_info *pBestIdx = pLevel->pBestIdx;
zMsg = sqlite3MPrintf("%z VIRTUAL TABLE INDEX %d:%s", zMsg,
pIdxInfo->idxNum, pIdxInfo->idxStr);
pBestIdx->idxNum, pBestIdx->idxStr);
}
#endif
if( pLevel->flags & WHERE_ORDERBY ){
@@ -1915,7 +1959,7 @@ WhereInfo *sqlite3WhereBegin(
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
if( pTab->isEphem || pTab->pSelect ) continue;
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( pLevel->pIdxInfo ){
if( pLevel->pBestIdx ){
int iCur = pTabItem->iCursor;
sqlite3VdbeOp3(v, OP_VOpen, iCur, 0, (const char*)pTab->pVtab, P3_VTAB);
}else
@@ -1988,17 +2032,17 @@ WhereInfo *sqlite3WhereBegin(
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( pLevel->pIdxInfo ){
if( pLevel->pBestIdx ){
/* Case 0: The table is a virtual-table. Use the VFilter and VNext
** to access the data.
*/
int ii;
sqlite3_index_info *pIdxInfo = pLevel->pIdxInfo;
int nConstraint = pIdxInfo->nConstraint;
sqlite3_index_info *pBestIdx = pLevel->pBestIdx;
int nConstraint = pBestIdx->nConstraint;
struct sqlite3_index_constraint_usage *aUsage =
pIdxInfo->aConstraintUsage;
pBestIdx->aConstraintUsage;
const struct sqlite3_index_constraint *aConstraint =
pIdxInfo->aConstraint;
pBestIdx->aConstraint;
for(ii=1; ii<=nConstraint; ii++){
int j;
@@ -2012,12 +2056,12 @@ WhereInfo *sqlite3WhereBegin(
if( j==nConstraint ) break;
}
sqlite3VdbeAddOp(v, OP_Integer, ii-1, 0);
sqlite3VdbeAddOp(v, OP_Integer, pIdxInfo->idxNum, 0);
sqlite3VdbeOp3(v, OP_VFilter, iCur, brk, pIdxInfo->idxStr,
pIdxInfo->needToFreeIdxStr ? P3_MPRINTF : P3_STATIC);
pIdxInfo->needToFreeIdxStr = 0;
for(ii=0; ii<pIdxInfo->nConstraint; ii++){
if( pIdxInfo->aConstraintUsage[ii].omit ){
sqlite3VdbeAddOp(v, OP_Integer, pBestIdx->idxNum, 0);
sqlite3VdbeOp3(v, OP_VFilter, iCur, brk, pBestIdx->idxStr,
pBestIdx->needToFreeIdxStr ? P3_MPRINTF : P3_STATIC);
pBestIdx->needToFreeIdxStr = 0;
for(ii=0; ii<pBestIdx->nConstraint; ii++){
if( pBestIdx->aConstraintUsage[ii].omit ){
disableTerm(pLevel, &wc.a[ii]);
}
}