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Wrap all automatic index changes inside SQLITE_OMIT_AUTOMATIC_INDEX. Add

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the automatic_index PRAGMA to turn it on and off.

FossilOrigin-Name: a811a47fbe4f757a7ab575ae5a0f65177a3f07c0
This commit is contained in:
drh
2010-04-07 16:54:58 +00:00
parent 4139c99eba
commit c633908199
9 changed files with 62 additions and 30 deletions
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38
src/where.c
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@@ -1637,6 +1637,7 @@ static void bestOrClauseIndex(
#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
}
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
/*
** Return TRUE if the WHERE clause term pTerm is of a form where it
** could be used with an index to access pSrc, assuming an appropriate
@@ -1655,7 +1656,9 @@ static int termCanDriveIndex(
if( !sqlite3IndexAffinityOk(pTerm->pExpr, aff) ) return 0;
return 1;
}
#endif
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
/*
** If the query plan for pSrc specified in pCost is a full table scan
** and indexing is allows (if there is no NOT INDEXED clause) and it
@@ -1664,7 +1667,7 @@ static int termCanDriveIndex(
** is taken into account, then alter the query plan to use the
** transient index.
*/
static void bestTransientIndex(
static void bestAutomaticIndex(
Parse *pParse, /* The parsing context */
WhereClause *pWC, /* The WHERE clause */
struct SrcList_item *pSrc, /* The FROM clause term to search */
@@ -1678,6 +1681,10 @@ static void bestTransientIndex(
WhereTerm *pWCEnd; /* End of pWC->a[] */
Table *pTable; /* Table tht might be indexed */
if( (pParse->db->flags & SQLITE_AutoIndex)==0 ){
/* Automatic indices are disabled at run-time */
return;
}
if( (pCost->plan.wsFlags & WHERE_NOT_FULLSCAN)!=0 ){
/* We already have some kind of index in use for this query. */
return;
@@ -1712,12 +1719,18 @@ static void bestTransientIndex(
}
}
}
#else
# define bestAutomaticIndex(A,B,C,D,E) /* no-op */
#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
/*
** Generate code to construct a transient index. Also create the
** corresponding Index structure and put it in pLevel->plan.u.pIdx.
** Generate code to construct the Index object for an automatic index
** and to set up the WhereLevel object pLevel so that the code generator
** makes use of the automatic index.
*/
static void constructTransientIndex(
static void constructAutomaticIndex(
Parse *pParse, /* The parsing context */
WhereClause *pWC, /* The WHERE clause */
struct SrcList_item *pSrc, /* The FROM clause term to get the next index */
@@ -1811,7 +1824,8 @@ static void constructTransientIndex(
}
assert( n==pLevel->plan.nEq );
/* Add additional columns needed to make the index into a covering index */
/* Add additional columns needed to make the automatic index into
** a covering index */
for(i=0; i<mxBitCol; i++){
if( extraCols & (1<<i) ){
pIdx->aiColumn[n] = i;
@@ -1828,14 +1842,14 @@ static void constructTransientIndex(
}
assert( n==nColumn );
/* Create the transient index */
/* Create the automatic index */
pKeyinfo = sqlite3IndexKeyinfo(pParse, pIdx);
assert( pLevel->iIdxCur>=0 );
sqlite3VdbeAddOp4(v, OP_OpenAutoindex, pLevel->iIdxCur, nColumn+1, 0,
(char*)pKeyinfo, P4_KEYINFO_HANDOFF);
VdbeComment((v, "for %s", pTable->zName));
/* Fill the transient index with content */
/* Fill the automatic index with content */
addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur);
regRecord = sqlite3GetTempReg(pParse);
sqlite3GenerateIndexKey(pParse, pIdx, pLevel->iTabCur, regRecord, 1);
@@ -1849,6 +1863,7 @@ static void constructTransientIndex(
/* Jump here when skipping the initialization */
sqlite3VdbeJumpHere(v, addrInit);
}
#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
@@ -2744,7 +2759,7 @@ static void bestBtreeIndex(
));
bestOrClauseIndex(pParse, pWC, pSrc, notReady, pOrderBy, pCost);
bestTransientIndex(pParse, pWC, pSrc, notReady, pCost);
bestAutomaticIndex(pParse, pWC, pSrc, notReady, pCost);
pCost->plan.wsFlags |= eqTermMask;
}
@@ -4151,9 +4166,12 @@ WhereInfo *sqlite3WhereBegin(
}else{
sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
}
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
if( (pLevel->plan.wsFlags & WHERE_TEMP_INDEX)!=0 ){
constructTransientIndex(pParse, pWC, pTabItem, notReady, pLevel);
}else if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){
constructAutomaticIndex(pParse, pWC, pTabItem, notReady, pLevel);
}else
#endif
if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){
Index *pIx = pLevel->plan.u.pIdx;
KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIx);
int iIdxCur = pLevel->iIdxCur;