** 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 1.339 2008/12/20 02:06:14 drh Exp $
+** $Id: where.c,v 1.340 2008/12/21 03:51:16 drh Exp $
*/
#include "sqliteInt.h"
#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
int sqlite3WhereTrace = 0;
#endif
-#if 0
+#if 1
# define WHERETRACE(X) if(sqlite3WhereTrace) sqlite3DebugPrintf X
#else
# define WHERETRACE(X)
/* Forward reference
*/
typedef struct WhereClause WhereClause;
-typedef struct ExprMaskSet ExprMaskSet;
+typedef struct WhereMaskSet WhereMaskSet;
typedef struct WhereOrInfo WhereOrInfo;
typedef struct WhereAndInfo WhereAndInfo;
+typedef struct WhereCost WhereCost;
/*
** The query generator uses an array of instances of this structure to
** but no other fields in the WhereTerm object are meaningful.
**
** When eOperator!=0, prereqRight and prereqAll record sets of cursor numbers,
-** but they do so indirectly. A single ExprMaskSet structure translates
+** but they do so indirectly. A single WhereMaskSet structure translates
** cursor number into bits and the translated bit is stored in the prereq
** fields. The translation is used in order to maximize the number of
** bits that will fit in a Bitmask. The VDBE cursor numbers might be
** spread out over the non-negative integers. For example, the cursor
-** numbers might be 3, 8, 9, 10, 20, 23, 41, and 45. The ExprMaskSet
+** numbers might be 3, 8, 9, 10, 20, 23, 41, and 45. The WhereMaskSet
** translates these sparse cursor numbers into consecutive integers
** beginning with 0 in order to make the best possible use of the available
** bits in the Bitmask. So, in the example above, the cursor numbers
*/
struct WhereClause {
Parse *pParse; /* The parser context */
- ExprMaskSet *pMaskSet; /* Mapping of table indices to bitmasks */
+ WhereMaskSet *pMaskSet; /* Mapping of table cursor numbers to bitmasks */
int nTerm; /* Number of terms */
int nSlot; /* Number of entries in a[] */
WhereTerm *a; /* Each a[] describes a term of the WHERE cluase */
** a dynamically allocated instance of the following structure.
*/
struct WhereOrInfo {
- WhereClause wc; /* The OR subexpression broken out */
+ WhereClause wc; /* Decomposition into subterms */
Bitmask indexable; /* Bitmask of all indexable tables in the clause */
+ WherePlan *aPlan; /* Search plan for each subterm */
};
/*
** from the sparse cursor numbers into consecutive integers beginning
** with 0.
**
-** If ExprMaskSet.ix[A]==B it means that The A-th bit of a Bitmask
+** If WhereMaskSet.ix[A]==B it means that The A-th bit of a Bitmask
** corresponds VDBE cursor number B. The A-th bit of a bitmask is 1<<A.
**
** For example, if the WHERE clause expression used these VDBE
-** cursors: 4, 5, 8, 29, 57, 73. Then the ExprMaskSet structure
+** cursors: 4, 5, 8, 29, 57, 73. Then the WhereMaskSet structure
** would map those cursor numbers into bits 0 through 5.
**
** Note that the mapping is not necessarily ordered. In the example
** numbers all get mapped into bit numbers that begin with 0 and contain
** no gaps.
*/
-struct ExprMaskSet {
+struct WhereMaskSet {
int n; /* Number of assigned cursor values */
int ix[BMS]; /* Cursor assigned to each bit */
};
+/*
+** A WhereCost object records a lookup strategy and the estimated
+** cost of pursuing that strategy.
+*/
+struct WhereCost {
+ WherePlan plan; /* The lookup strategy */
+ double rCost; /* Overall cost of pursuing this search strategy */
+ double nRow; /* Estimated number of output rows */
+};
/*
** Bitmasks for the operators that indices are able to exploit. An
#define WHERE_COLUMN_EQ 0x00010000 /* x=EXPR or x IN (...) */
#define WHERE_COLUMN_RANGE 0x00020000 /* x<EXPR and/or x>EXPR */
#define WHERE_COLUMN_IN 0x00040000 /* x IN (...) */
+#define WHERE_INDEXED 0x00070000 /* Anything that uses an index */
+#define WHERE_IN_ABLE 0x00071000 /* Able to support an IN operator */
#define WHERE_TOP_LIMIT 0x00100000 /* x<EXPR or x<=EXPR constraint */
#define WHERE_BTM_LIMIT 0x00200000 /* x>EXPR or x>=EXPR constraint */
#define WHERE_IDX_ONLY 0x00800000 /* Use index only - omit table */
static void whereClauseInit(
WhereClause *pWC, /* The WhereClause to be initialized */
Parse *pParse, /* The parsing context */
- ExprMaskSet *pMaskSet /* Mapping from table indices to bitmasks */
+ WhereMaskSet *pMaskSet /* Mapping from table cursor numbers to bitmasks */
){
pWC->pParse = pParse;
pWC->pMaskSet = pMaskSet;
static void whereOrInfoDelete(sqlite3 *db, WhereOrInfo *p){
if( p ){
whereClauseClear(&p->wc);
+ sqlite3DbFree(db, p->aPlan);
sqlite3DbFree(db, p);
}
}
** Return the bitmask for the given cursor number. Return 0 if
** iCursor is not in the set.
*/
-static Bitmask getMask(ExprMaskSet *pMaskSet, int iCursor){
+static Bitmask getMask(WhereMaskSet *pMaskSet, int iCursor){
int i;
for(i=0; i<pMaskSet->n; i++){
if( pMaskSet->ix[i]==iCursor ){
** sqlite3WhereBegin() routine. So we know that the pMaskSet->ix[]
** array will never overflow.
*/
-static void createMask(ExprMaskSet *pMaskSet, int iCursor){
+static void createMask(WhereMaskSet *pMaskSet, int iCursor){
assert( pMaskSet->n < ArraySize(pMaskSet->ix) );
pMaskSet->ix[pMaskSet->n++] = iCursor;
}
** translate the cursor numbers into bitmask values and OR all
** the bitmasks together.
*/
-static Bitmask exprListTableUsage(ExprMaskSet*, ExprList*);
-static Bitmask exprSelectTableUsage(ExprMaskSet*, Select*);
-static Bitmask exprTableUsage(ExprMaskSet *pMaskSet, Expr *p){
+static Bitmask exprListTableUsage(WhereMaskSet*, ExprList*);
+static Bitmask exprSelectTableUsage(WhereMaskSet*, Select*);
+static Bitmask exprTableUsage(WhereMaskSet *pMaskSet, Expr *p){
Bitmask mask = 0;
if( p==0 ) return 0;
if( p->op==TK_COLUMN ){
mask |= exprSelectTableUsage(pMaskSet, p->pSelect);
return mask;
}
-static Bitmask exprListTableUsage(ExprMaskSet *pMaskSet, ExprList *pList){
+static Bitmask exprListTableUsage(WhereMaskSet *pMaskSet, ExprList *pList){
int i;
Bitmask mask = 0;
if( pList ){
}
return mask;
}
-static Bitmask exprSelectTableUsage(ExprMaskSet *pMaskSet, Select *pS){
+static Bitmask exprSelectTableUsage(WhereMaskSet *pMaskSet, Select *pS){
Bitmask mask = 0;
while( pS ){
mask |= exprListTableUsage(pMaskSet, pS->pEList);
sqlite3 *db = pParse->db; /* Database connection */
WhereTerm *pTerm = &pWC->a[idxTerm]; /* The term to be analyzed */
Expr *pExpr = pTerm->pExpr; /* The expression of the term */
- ExprMaskSet *pMaskSet = pWC->pMaskSet; /* Table use masks */
+ WhereMaskSet *pMaskSet = pWC->pMaskSet; /* Table use masks */
int i; /* Loop counters */
WhereClause *pOrWc; /* Breakup of pTerm into subterms */
WhereTerm *pOrTerm; /* A Sub-term within the pOrWc */
pTerm->wtFlags |= TERM_ORINFO;
pOrWc = &pOrInfo->wc;
whereClauseInit(pOrWc, pWC->pParse, pMaskSet);
+ pOrInfo->aPlan = 0;
whereSplit(pOrWc, pExpr, TK_OR);
exprAnalyzeAll(pSrc, pOrWc);
if( db->mallocFailed ) return;
/*
** Record the set of tables that satisfy case 2. The set might be
- ** empty, but that is OK.
+ ** empty.
*/
pOrInfo->indexable = indexable;
- pTerm->eOperator = WO_OR;
+ pTerm->eOperator = indexable==0 ? 0 : WO_OR;
/*
** chngToIN holds a set of tables that *might* satisfy case 1. But
pTerm->eOperator = 0; /* case 1 trumps case 2 */
}
}
+
+ /* If case 2 applies, allocate space for pOrInfo->aPlan
+ */
+ if( pTerm->eOperator==WO_OR ){
+ pOrInfo->aPlan = sqlite3DbMallocRaw(db, pOrWc->nTerm*sizeof(WherePlan));
+ }
}
#endif /* !SQLITE_OMIT_OR_OPTIMIZATION && !SQLITE_OMIT_SUBQUERY */
int idxTerm /* Index of the term to be analyzed */
){
WhereTerm *pTerm; /* The term to be analyzed */
- ExprMaskSet *pMaskSet; /* Set of table index masks */
+ WhereMaskSet *pMaskSet; /* Set of table index masks */
Expr *pExpr; /* The expression to be analyzed */
Bitmask prereqLeft; /* Prerequesites of the pExpr->pLeft */
Bitmask prereqAll; /* Prerequesites of pExpr */
*/
static int referencesOtherTables(
ExprList *pList, /* Search expressions in ths list */
- ExprMaskSet *pMaskSet, /* Mapping from tables to bitmaps */
+ WhereMaskSet *pMaskSet, /* Mapping from tables to bitmaps */
int iFirst, /* Be searching with the iFirst-th expression */
int iBase /* Ignore references to this table */
){
*/
static int isSortingIndex(
Parse *pParse, /* Parsing context */
- ExprMaskSet *pMaskSet, /* Mapping from table indices to bitmaps */
+ WhereMaskSet *pMaskSet, /* Mapping from table cursor numbers to bitmaps */
Index *pIdx, /* The index we are testing */
int base, /* Cursor number for the table to be sorted */
ExprList *pOrderBy, /* The ORDER BY clause */
static int sortableByRowid(
int base, /* Cursor number for table to be sorted */
ExprList *pOrderBy, /* The ORDER BY clause */
- ExprMaskSet *pMaskSet, /* Mapping from tables to bitmaps */
+ WhereMaskSet *pMaskSet, /* Mapping from table cursors to bitmaps */
int *pbRev /* Set to 1 if ORDER BY is DESC */
){
Expr *p;
#endif /* SQLITE_OMIT_VIRTUALTABLE */
/*
-** Find the best index for accessing a particular table. Return a pointer
-** to the index, flags that describe how the index should be used, the
-** number of equality constraints, and the "cost" for this index.
+** Find the query plan for accessing a particular table. Write the
+** best query plan and its cost into the WhereCost object supplied as the
+** last parameter.
**
-** The lowest cost index wins. The cost is an estimate of the amount of
-** CPU and disk I/O need to process the request using the selected index.
+** The lowest cost plan wins. The cost is an estimate of the amount of
+** CPU and disk I/O need to process the request using the selected plan.
** Factors that influence cost include:
**
** * The estimated number of rows that will be retrieved. (The
** index and in the main table.
**
** If there was an INDEXED BY clause attached to the table in the SELECT
-** statement, then this function only considers strategies using the
+** statement, then this function only considers plans using the
** named index. If one cannot be found, then the returned cost is
-** SQLITE_BIG_DBL. If a strategy can be found that uses the named index,
+** SQLITE_BIG_DBL. If a plan can be found that uses the named index,
** then the cost is calculated in the usual way.
**
** If a NOT INDEXED clause was attached to the table in the SELECT
** statement, then no indexes are considered. However, the selected
-** stategy may still take advantage of the tables built-in rowid
+** plan may still take advantage of the tables built-in rowid
** index.
*/
-static double bestIndex(
+static void bestIndex(
Parse *pParse, /* The parsing context */
WhereClause *pWC, /* The WHERE clause */
struct SrcList_item *pSrc, /* The FROM clause term to search */
Bitmask notReady, /* Mask of cursors that are not available */
- ExprList *pOrderBy, /* The order by clause */
- Index **ppIndex, /* Make *ppIndex point to the best index */
- int *pWsFlags, /* Put wsFlags describing scan strategy here */
- int *pnEq /* Put the number of == or IN constraints here */
+ ExprList *pOrderBy, /* The ORDER BY clause */
+ WhereCost *pCost /* Lowest cost query plan */
){
- WhereTerm *pTerm;
- Index *bestIdx = 0; /* Index that gives the lowest cost */
- double lowestCost; /* The cost of using bestIdx */
- int bestWsFlags = 0; /* Flags associated with bestIdx */
- int bestNEq = 0; /* Best value for nEq */
+ WhereTerm *pTerm; /* A single term of the WHERE clause */
int iCur = pSrc->iCursor; /* The cursor of the table to be accessed */
Index *pProbe; /* An index we are evaluating */
int rev; /* True to scan in reverse order */
int nEq; /* Number of == or IN constraints */
int eqTermMask; /* Mask of valid equality operators */
double cost; /* Cost of using pProbe */
+ double nRow; /* Estimated number of rows in result set */
WHERETRACE(("bestIndex: tbl=%s notReady=%llx\n", pSrc->pTab->zName,notReady));
- lowestCost = SQLITE_BIG_DBL;
pProbe = pSrc->pTab->pIndex;
if( pSrc->notIndexed ){
pProbe = 0;
** well put it first in the join order. That way, perhaps it can be
** referenced by other tables in the join.
*/
+ memset(pCost, 0, sizeof(*pCost));
if( pProbe==0 &&
findTerm(pWC, iCur, -1, 0, WO_EQ|WO_IN|WO_LT|WO_LE|WO_GT|WO_GE,0)==0 &&
(pOrderBy==0 || !sortableByRowid(iCur, pOrderBy, pWC->pMaskSet, &rev)) ){
- *pWsFlags = 0;
- *ppIndex = 0;
- *pnEq = 0;
- return 0.0;
+ return;
}
+ pCost->rCost = SQLITE_BIG_DBL;
/* Check for a rowid=EXPR or rowid IN (...) constraints. If there was
** an INDEXED BY clause attached to this table, skip this step.
pTerm = findTerm(pWC, iCur, -1, notReady, WO_EQ|WO_IN, 0);
if( pTerm ){
Expr *pExpr;
- *ppIndex = 0;
- bestWsFlags = WHERE_ROWID_EQ;
+ pCost->plan.wsFlags = WHERE_ROWID_EQ;
if( pTerm->eOperator & WO_EQ ){
/* Rowid== is always the best pick. Look no further. Because only
** a single row is generated, output is always in sorted order */
- *pWsFlags = WHERE_ROWID_EQ | WHERE_UNIQUE;
- *pnEq = 1;
+ pCost->plan.wsFlags = WHERE_ROWID_EQ | WHERE_UNIQUE;
+ pCost->plan.nEq = 1;
WHERETRACE(("... best is rowid\n"));
- return 0.0;
+ pCost->rCost = 0;
+ pCost->nRow = 1;
+ return;
}else if( (pExpr = pTerm->pExpr)->pList!=0 ){
/* Rowid IN (LIST): cost is NlogN where N is the number of list
** elements. */
- lowestCost = pExpr->pList->nExpr;
- lowestCost *= estLog(lowestCost);
+ pCost->rCost = pCost->nRow = pExpr->pList->nExpr;
+ pCost->rCost *= estLog(pCost->rCost);
}else{
/* Rowid IN (SELECT): cost is NlogN where N is the number of rows
** in the result of the inner select. We have no way to estimate
** that value so make a wild guess. */
- lowestCost = 200;
+ pCost->nRow = 100;
+ pCost->rCost = 200;
}
- WHERETRACE(("... rowid IN cost: %.9g\n", lowestCost));
+ WHERETRACE(("... rowid IN cost: %.9g\n", pCost->rCost));
}
/* Estimate the cost of a table scan. If we do not know how many
}else{
wsFlags = 0;
}
+ nRow = cost;
/* If the table scan does not satisfy the ORDER BY clause, increase
** the cost by NlogN to cover the expense of sorting. */
WHERETRACE(("... sorting increases cost to %.9g\n", cost));
}
}
- if( cost<lowestCost ){
- lowestCost = cost;
- bestWsFlags = wsFlags;
+ if( cost<pCost->rCost ){
+ pCost->rCost = cost;
+ pCost->nRow = nRow;
+ pCost->plan.wsFlags = wsFlags;
}
}
}
}
}
- cost = pProbe->aiRowEst[i] * inMultiplier * estLog(inMultiplier);
+ nRow = pProbe->aiRowEst[i] * inMultiplier;
+ cost = nRow * estLog(inMultiplier);
nEq = i;
if( pProbe->onError!=OE_None && (wsFlags & WHERE_COLUMN_IN)==0
&& nEq==pProbe->nColumn ){
if( findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE, pProbe) ){
wsFlags |= WHERE_TOP_LIMIT;
cost /= 3;
+ nRow /= 3;
}
if( findTerm(pWC, iCur, j, notReady, WO_GT|WO_GE, pProbe) ){
wsFlags |= WHERE_BTM_LIMIT;
cost /= 3;
+ nRow /= 3;
}
WHERETRACE(("...... range reduces cost to %.9g\n", cost));
}
/* If this index has achieved the lowest cost so far, then use it.
*/
- if( wsFlags && cost < lowestCost ){
- bestIdx = pProbe;
- lowestCost = cost;
- bestWsFlags = wsFlags;
- bestNEq = nEq;
+ if( wsFlags!=0 && cost < pCost->rCost ){
+ pCost->rCost = cost;
+ pCost->nRow = nRow;
+ pCost->plan.wsFlags = wsFlags;
+ pCost->plan.nEq = nEq;
+ assert( pCost->plan.wsFlags & WHERE_INDEXED );
+ pCost->plan.u.pIdx = pProbe;
}
}
/* Report the best result
*/
- *ppIndex = bestIdx;
- WHERETRACE(("best index is %s, cost=%.9g, wsFlags=%x, nEq=%d\n",
- bestIdx ? bestIdx->zName : "(none)", lowestCost, bestWsFlags, bestNEq));
- *pWsFlags = bestWsFlags | eqTermMask;
- *pnEq = bestNEq;
- return lowestCost;
+ pCost->plan.wsFlags |= eqTermMask;
+ WHERETRACE(("best index is %s, cost=%.9g, nrow=%.9g, wsFlags=%x, nEq=%d\n",
+ (pCost->plan.wsFlags & WHERE_INDEXED)!=0 ?
+ pCost->plan.u.pIdx->zName : "(none)", pCost->nRow,
+ pCost->rCost, pCost->plan.wsFlags, pCost->plan.nEq));
}
iTab = pX->iTable;
sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);
VdbeComment((v, "%.*s", pX->span.n, pX->span.z));
- if( pLevel->nIn==0 ){
+ assert( pLevel->plan.wsFlags & WHERE_IN_ABLE );
+ if( pLevel->u.in.nIn==0 ){
pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
}
- pLevel->nIn++;
- pLevel->aInLoop = sqlite3DbReallocOrFree(pParse->db, pLevel->aInLoop,
- sizeof(pLevel->aInLoop[0])*pLevel->nIn);
- pIn = pLevel->aInLoop;
+ pLevel->u.in.nIn++;
+ pLevel->u.in.aInLoop =
+ sqlite3DbReallocOrFree(pParse->db, pLevel->u.in.aInLoop,
+ sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);
+ pIn = pLevel->u.in.aInLoop;
if( pIn ){
- pIn += pLevel->nIn - 1;
+ pIn += pLevel->u.in.nIn - 1;
pIn->iCur = iTab;
if( eType==IN_INDEX_ROWID ){
pIn->addrInTop = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iReg);
}
sqlite3VdbeAddOp1(v, OP_IsNull, iReg);
}else{
- pLevel->nIn = 0;
+ pLevel->u.in.nIn = 0;
}
#endif
}
Bitmask notReady, /* Which parts of FROM have not yet been coded */
int nExtraReg /* Number of extra registers to allocate */
){
- int nEq = pLevel->nEq; /* The number of == or IN constraints to code */
- Vdbe *v = pParse->pVdbe; /* The virtual machine under construction */
- Index *pIdx = pLevel->pIdx; /* The index being used for this loop */
+ int nEq = pLevel->plan.nEq; /* The number of == or IN constraints to code */
+ Vdbe *v = pParse->pVdbe; /* The vm under construction */
+ Index *pIdx; /* The index being used for this loop */
int iCur = pLevel->iTabCur; /* The cursor of the table */
WhereTerm *pTerm; /* A single constraint term */
int j; /* Loop counter */
int regBase; /* Base register */
+ /* This module is only called on query plans that use an index. */
+ assert( pLevel->plan.wsFlags & WHERE_INDEXED );
+ pIdx = pLevel->plan.u.pIdx;
+
/* Figure out how many memory cells we will need then allocate them.
** We always need at least one used to store the loop terminator
** value. If there are IN operators we'll need one for each == or
** IN constraint.
*/
regBase = pParse->nMem + 1;
- pParse->nMem += pLevel->nEq + 1 + nExtraReg;
+ pParse->nMem += pLevel->plan.nEq + 1 + nExtraReg;
/* Evaluate the equality constraints
*/
for(j=0; j<nEq; j++){
int r1;
int k = pIdx->aiColumn[j];
- pTerm = findTerm(pWC, iCur, k, notReady, pLevel->wsFlags, pIdx);
+ pTerm = findTerm(pWC, iCur, k, notReady, pLevel->plan.wsFlags, pIdx);
if( NEVER(pTerm==0) ) break;
assert( (pTerm->wtFlags & TERM_CODED)==0 );
r1 = codeEqualityTerm(pParse, pTerm, pLevel, regBase+j);
return regBase;
}
+/*
+** Generate code for the start of the iLevel-th loop in the WHERE clause
+** implementation described by pWInfo.
+*/
+static Bitmask codeOneLoopStart(
+ WhereInfo *pWInfo, /* Complete information about the WHERE clause */
+ int iLevel, /* Which level of pWInfo->a[] should be coded */
+ u8 wctrlFlags, /* One of the WHERE_* flags defined in sqliteInt.h */
+ Bitmask notReady /* Which tables are currently available */
+){
+ int j, k; /* Loop counters */
+ int iCur; /* The VDBE cursor for the table */
+ int addrNxt; /* Where to jump to continue with the next IN case */
+ int omitTable; /* True if we use the index only */
+ int bRev; /* True if we need to scan in reverse order */
+ WhereLevel *pLevel; /* The where level to be coded */
+ WhereClause *pWC; /* Decomposition of the entire WHERE clause */
+ WhereTerm *pTerm; /* A WHERE clause term */
+ Parse *pParse; /* Parsing context */
+ Vdbe *v; /* The prepared stmt under constructions */
+ struct SrcList_item *pTabItem; /* FROM clause term being coded */
+ int addrBrk;
+ int addrCont;
+
+
+ pParse = pWInfo->pParse;
+ v = pParse->pVdbe;
+ pWC = pWInfo->pWC;
+ pLevel = &pWInfo->a[iLevel];
+ pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
+ iCur = pTabItem->iCursor;
+ bRev = (pLevel->plan.wsFlags & WHERE_REVERSE)!=0;
+ omitTable = (pLevel->plan.wsFlags & WHERE_IDX_ONLY)!=0;
+
+ /* Create labels for the "break" and "continue" instructions
+ ** for the current loop. Jump to addrBrk to break out of a loop.
+ ** Jump to cont to go immediately to the next iteration of the
+ ** loop.
+ **
+ ** When there is an IN operator, we also have a "addrNxt" label that
+ ** means to continue with the next IN value combination. When
+ ** there are no IN operators in the constraints, the "addrNxt" label
+ ** is the same as "addrBrk".
+ */
+ addrBrk = pLevel->addrBrk = pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
+ addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(v);
+
+ /* If this is the right table of a LEFT OUTER JOIN, allocate and
+ ** initialize a memory cell that records if this table matches any
+ ** row of the left table of the join.
+ */
+ if( pLevel->iFrom>0 && (pTabItem[0].jointype & JT_LEFT)!=0 ){
+ pLevel->iLeftJoin = ++pParse->nMem;
+ sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
+ VdbeComment((v, "init LEFT JOIN no-match flag"));
+ }
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+ if( (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){
+ /* Case 0: The table is a virtual-table. Use the VFilter and VNext
+ ** to access the data.
+ */
+ int iReg; /* P3 Value for OP_VFilter */
+ sqlite3_index_info *pVtabIdx = pLevel->plan.u.pVtabIdx;
+ int nConstraint = pVtabIdx->nConstraint;
+ struct sqlite3_index_constraint_usage *aUsage =
+ pVtabIdx->aConstraintUsage;
+ const struct sqlite3_index_constraint *aConstraint =
+ pVtabIdx->aConstraint;
+
+ iReg = sqlite3GetTempRange(pParse, nConstraint+2);
+ pParse->disableColCache++;
+ for(j=1; j<=nConstraint; j++){
+ for(k=0; k<nConstraint; k++){
+ if( aUsage[k].argvIndex==j ){
+ int iTerm = aConstraint[k].iTermOffset;
+ assert( pParse->disableColCache );
+ sqlite3ExprCode(pParse, pWC->a[iTerm].pExpr->pRight, iReg+j+1);
+ break;
+ }
+ }
+ if( k==nConstraint ) break;
+ }
+ assert( pParse->disableColCache );
+ pParse->disableColCache--;
+ sqlite3VdbeAddOp2(v, OP_Integer, pVtabIdx->idxNum, iReg);
+ sqlite3VdbeAddOp2(v, OP_Integer, j-1, iReg+1);
+ sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrBrk, iReg, pVtabIdx->idxStr,
+ pVtabIdx->needToFreeIdxStr ? P4_MPRINTF : P4_STATIC);
+ sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
+ pVtabIdx->needToFreeIdxStr = 0;
+ for(j=0; j<nConstraint; j++){
+ if( aUsage[j].omit ){
+ int iTerm = aConstraint[j].iTermOffset;
+ disableTerm(pLevel, &pWC->a[iTerm]);
+ }
+ }
+ pLevel->op = OP_VNext;
+ pLevel->p1 = iCur;
+ pLevel->p2 = sqlite3VdbeCurrentAddr(v);
+ }else
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+ if( pLevel->plan.wsFlags & WHERE_ROWID_EQ ){
+ /* Case 1: We can directly reference a single row using an
+ ** equality comparison against the ROWID field. Or
+ ** we reference multiple rows using a "rowid IN (...)"
+ ** construct.
+ */
+ int r1;
+ int rtmp = sqlite3GetTempReg(pParse);
+ pTerm = findTerm(pWC, iCur, -1, notReady, WO_EQ|WO_IN, 0);
+ assert( pTerm!=0 );
+ assert( pTerm->pExpr!=0 );
+ assert( pTerm->leftCursor==iCur );
+ assert( omitTable==0 );
+ r1 = codeEqualityTerm(pParse, pTerm, pLevel, rtmp);
+ addrNxt = pLevel->addrNxt;
+ sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, addrNxt);
+ sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addrNxt, r1);
+ sqlite3ReleaseTempReg(pParse, rtmp);
+ VdbeComment((v, "pk"));
+ pLevel->op = OP_Noop;
+ }else if( pLevel->plan.wsFlags & WHERE_ROWID_RANGE ){
+ /* Case 2: We have an inequality comparison against the ROWID field.
+ */
+ int testOp = OP_Noop;
+ int start;
+ int memEndValue = 0;
+ WhereTerm *pStart, *pEnd;
+
+ assert( omitTable==0 );
+ pStart = findTerm(pWC, iCur, -1, notReady, WO_GT|WO_GE, 0);
+ pEnd = findTerm(pWC, iCur, -1, notReady, WO_LT|WO_LE, 0);
+ if( bRev ){
+ pTerm = pStart;
+ pStart = pEnd;
+ pEnd = pTerm;
+ }
+ if( pStart ){
+ Expr *pX; /* The expression that defines the start bound */
+ int r1, rTemp; /* Registers for holding the start boundary */
+
+ /* The following constant maps TK_xx codes into corresponding
+ ** seek opcodes. It depends on a particular ordering of TK_xx
+ */
+ const u8 aMoveOp[] = {
+ /* TK_GT */ OP_SeekGt,
+ /* TK_LE */ OP_SeekLe,
+ /* TK_LT */ OP_SeekLt,
+ /* TK_GE */ OP_SeekGe
+ };
+ assert( TK_LE==TK_GT+1 ); /* Make sure the ordering.. */
+ assert( TK_LT==TK_GT+2 ); /* ... of the TK_xx values... */
+ assert( TK_GE==TK_GT+3 ); /* ... is correcct. */
+
+ pX = pStart->pExpr;
+ assert( pX!=0 );
+ assert( pStart->leftCursor==iCur );
+ r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
+ sqlite3VdbeAddOp3(v, aMoveOp[pX->op-TK_GT], iCur, addrBrk, r1);
+ VdbeComment((v, "pk"));
+ sqlite3ExprCacheAffinityChange(pParse, r1, 1);
+ sqlite3ReleaseTempReg(pParse, rTemp);
+ disableTerm(pLevel, pStart);
+ }else{
+ sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrBrk);
+ }
+ if( pEnd ){
+ Expr *pX;
+ pX = pEnd->pExpr;
+ assert( pX!=0 );
+ assert( pEnd->leftCursor==iCur );
+ memEndValue = ++pParse->nMem;
+ sqlite3ExprCode(pParse, pX->pRight, memEndValue);
+ if( pX->op==TK_LT || pX->op==TK_GT ){
+ testOp = bRev ? OP_Le : OP_Ge;
+ }else{
+ testOp = bRev ? OP_Lt : OP_Gt;
+ }
+ disableTerm(pLevel, pEnd);
+ }
+ start = sqlite3VdbeCurrentAddr(v);
+ pLevel->op = bRev ? OP_Prev : OP_Next;
+ pLevel->p1 = iCur;
+ pLevel->p2 = start;
+ if( testOp!=OP_Noop ){
+ int r1 = sqlite3GetTempReg(pParse);
+ sqlite3VdbeAddOp2(v, OP_Rowid, iCur, r1);
+ sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, r1);
+ sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
+ sqlite3ReleaseTempReg(pParse, r1);
+ }
+ }else if( pLevel->plan.wsFlags & (WHERE_COLUMN_RANGE|WHERE_COLUMN_EQ) ){
+ /* Case 3: A scan using an index.
+ **
+ ** The WHERE clause may contain zero or more equality
+ ** terms ("==" or "IN" operators) that refer to the N
+ ** left-most columns of the index. It may also contain
+ ** inequality constraints (>, <, >= or <=) on the indexed
+ ** column that immediately follows the N equalities. Only
+ ** the right-most column can be an inequality - the rest must
+ ** use the "==" and "IN" operators. For example, if the
+ ** index is on (x,y,z), then the following clauses are all
+ ** optimized:
+ **
+ ** x=5
+ ** x=5 AND y=10
+ ** x=5 AND y<10
+ ** x=5 AND y>5 AND y<10
+ ** x=5 AND y=5 AND z<=10
+ **
+ ** The z<10 term of the following cannot be used, only
+ ** the x=5 term:
+ **
+ ** x=5 AND z<10
+ **
+ ** N may be zero if there are inequality constraints.
+ ** If there are no inequality constraints, then N is at
+ ** least one.
+ **
+ ** This case is also used when there are no WHERE clause
+ ** constraints but an index is selected anyway, in order
+ ** to force the output order to conform to an ORDER BY.
+ */
+ int aStartOp[] = {
+ 0,
+ 0,
+ OP_Rewind, /* 2: (!start_constraints && startEq && !bRev) */
+ OP_Last, /* 3: (!start_constraints && startEq && bRev) */
+ OP_SeekGt, /* 4: (start_constraints && !startEq && !bRev) */
+ OP_SeekLt, /* 5: (start_constraints && !startEq && bRev) */
+ OP_SeekGe, /* 6: (start_constraints && startEq && !bRev) */
+ OP_SeekLe /* 7: (start_constraints && startEq && bRev) */
+ };
+ int aEndOp[] = {
+ OP_Noop, /* 0: (!end_constraints) */
+ OP_IdxGE, /* 1: (end_constraints && !bRev) */
+ OP_IdxLT /* 2: (end_constraints && bRev) */
+ };
+ int nEq = pLevel->plan.nEq;
+ int isMinQuery = 0; /* If this is an optimized SELECT min(x).. */
+ int regBase; /* Base register holding constraint values */
+ int r1; /* Temp register */
+ WhereTerm *pRangeStart = 0; /* Inequality constraint at range start */
+ WhereTerm *pRangeEnd = 0; /* Inequality constraint at range end */
+ int startEq; /* True if range start uses ==, >= or <= */
+ int endEq; /* True if range end uses ==, >= or <= */
+ int start_constraints; /* Start of range is constrained */
+ int nConstraint; /* Number of constraint terms */
+ Index *pIdx; /* The index we will be using */
+ int iIdxCur; /* The VDBE cursor for the index */
+ int op;
+
+ pIdx = pLevel->plan.u.pIdx;
+ iIdxCur = pLevel->iIdxCur;
+ k = pIdx->aiColumn[nEq]; /* Column for inequality constraints */
+
+ /* Generate code to evaluate all constraint terms using == or IN
+ ** and store the values of those terms in an array of registers
+ ** starting at regBase.
+ */
+ regBase = codeAllEqualityTerms(pParse, pLevel, pWC, notReady, 2);
+ addrNxt = pLevel->addrNxt;
+
+ /* If this loop satisfies a sort order (pOrderBy) request that
+ ** was passed to this function to implement a "SELECT min(x) ..."
+ ** query, then the caller will only allow the loop to run for
+ ** a single iteration. This means that the first row returned
+ ** should not have a NULL value stored in 'x'. If column 'x' is
+ ** the first one after the nEq equality constraints in the index,
+ ** this requires some special handling.
+ */
+ if( (wctrlFlags&WHERE_ORDERBY_MIN)!=0
+ && (pLevel->plan.wsFlags&WHERE_ORDERBY)
+ && (pIdx->nColumn>nEq)
+ ){
+ /* assert( pOrderBy->nExpr==1 ); */
+ /* assert( pOrderBy->a[0].pExpr->iColumn==pIdx->aiColumn[nEq] ); */
+ isMinQuery = 1;
+ }
+
+ /* Find any inequality constraint terms for the start and end
+ ** of the range.
+ */
+ if( pLevel->plan.wsFlags & WHERE_TOP_LIMIT ){
+ pRangeEnd = findTerm(pWC, iCur, k, notReady, (WO_LT|WO_LE), pIdx);
+ }
+ if( pLevel->plan.wsFlags & WHERE_BTM_LIMIT ){
+ pRangeStart = findTerm(pWC, iCur, k, notReady, (WO_GT|WO_GE), pIdx);
+ }
+
+ /* If we are doing a reverse order scan on an ascending index, or
+ ** a forward order scan on a descending index, interchange the
+ ** start and end terms (pRangeStart and pRangeEnd).
+ */
+ if( bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC) ){
+ SWAP(WhereTerm *, pRangeEnd, pRangeStart);
+ }
+
+ testcase( pRangeStart && pRangeStart->eOperator & WO_LE );
+ testcase( pRangeStart && pRangeStart->eOperator & WO_GE );
+ testcase( pRangeEnd && pRangeEnd->eOperator & WO_LE );
+ testcase( pRangeEnd && pRangeEnd->eOperator & WO_GE );
+ startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
+ endEq = !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
+ start_constraints = pRangeStart || nEq>0;
+
+ /* Seek the index cursor to the start of the range. */
+ nConstraint = nEq;
+ if( pRangeStart ){
+ int dcc = pParse->disableColCache;
+ if( pRangeEnd ){
+ pParse->disableColCache++;
+ }
+ sqlite3ExprCode(pParse, pRangeStart->pExpr->pRight, regBase+nEq);
+ pParse->disableColCache = dcc;
+ sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
+ nConstraint++;
+ }else if( isMinQuery ){
+ sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
+ nConstraint++;
+ startEq = 0;
+ start_constraints = 1;
+ }
+ codeApplyAffinity(pParse, regBase, nConstraint, pIdx);
+ op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
+ assert( op!=0 );
+ testcase( op==OP_Rewind );
+ testcase( op==OP_Last );
+ testcase( op==OP_SeekGt );
+ testcase( op==OP_SeekGe );
+ testcase( op==OP_SeekLe );
+ testcase( op==OP_SeekLt );
+ sqlite3VdbeAddOp4(v, op, iIdxCur, addrNxt, regBase,
+ SQLITE_INT_TO_PTR(nConstraint), P4_INT32);
+
+ /* Load the value for the inequality constraint at the end of the
+ ** range (if any).
+ */
+ nConstraint = nEq;
+ if( pRangeEnd ){
+ sqlite3ExprCode(pParse, pRangeEnd->pExpr->pRight, regBase+nEq);
+ sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
+ codeApplyAffinity(pParse, regBase, nEq+1, pIdx);
+ nConstraint++;
+ }
+
+ /* Top of the loop body */
+ pLevel->p2 = sqlite3VdbeCurrentAddr(v);
+
+ /* Check if the index cursor is past the end of the range. */
+ op = aEndOp[(pRangeEnd || nEq) * (1 + bRev)];
+ testcase( op==OP_Noop );
+ testcase( op==OP_IdxGE );
+ testcase( op==OP_IdxLT );
+ sqlite3VdbeAddOp4(v, op, iIdxCur, addrNxt, regBase,
+ SQLITE_INT_TO_PTR(nConstraint), P4_INT32);
+ sqlite3VdbeChangeP5(v, endEq!=bRev ?1:0);
+
+ /* If there are inequality constraints, check that the value
+ ** of the table column that the inequality contrains is not NULL.
+ ** If it is, jump to the next iteration of the loop.
+ */
+ r1 = sqlite3GetTempReg(pParse);
+ testcase( pLevel->plan.wsFlags & WHERE_BTM_LIMIT );
+ testcase( pLevel->plan.wsFlags & WHERE_TOP_LIMIT );
+ if( pLevel->plan.wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT) ){
+ sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, nEq, r1);
+ sqlite3VdbeAddOp2(v, OP_IsNull, r1, addrCont);
+ }
+
+ /* Seek the table cursor, if required */
+ if( !omitTable ){
+ sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, r1);
+ sqlite3VdbeAddOp2(v, OP_Seek, iCur, r1); /* Deferred seek */
+ }
+ sqlite3ReleaseTempReg(pParse, r1);
+
+ /* Record the instruction used to terminate the loop. Disable
+ ** WHERE clause terms made redundant by the index range scan.
+ */
+ pLevel->op = bRev ? OP_Prev : OP_Next;
+ pLevel->p1 = iIdxCur;
+ disableTerm(pLevel, pRangeStart);
+ disableTerm(pLevel, pRangeEnd);
+ }else if( pLevel->plan.wsFlags & WHERE_MULTI_OR ){
+ /* Case 4: Two or more separately indexed terms connected by OR
+ **
+ ** Example:
+ **
+ ** CREATE TABLE t1(a,b,c,d);
+ ** CREATE INDEX i1 ON t1(a);
+ ** CREATE INDEX i2 ON t1(b);
+ ** CREATE INDEX i3 ON t1(c);
+ **
+ ** SELECT * FROM t1 WHERE a=5 OR b=7 OR (c=11 AND d=13)
+ **
+ ** In the example, there are three indexed terms connected by OR.
+ ** The top of the loop is constructed by creating a RowSet object
+ ** and populating it. Then looping over elements of the rowset.
+ **
+ ** Null 1
+ ** # fill RowSet 1 with entries where a=5 using i1
+ ** # fill Rowset 1 with entries where b=7 using i2
+ ** # fill Rowset 1 with entries where c=11 and d=13 i3 and t1
+ ** A: RowSetRead 1, B, 2
+ ** Seek i, 2
+ **
+ ** The bottom of the loop looks like this:
+ **
+ ** Goto 0, A
+ ** B:
+ */
+ int regRowset; /* Register holding the RowSet object */
+ int regNextRowid; /* Register holding next rowid */
+ WhereTerm *pTerm; /* The complete OR-clause */
+ WhereClause *pOrWc; /* The OR-clause broken out into subterms */
+ WhereTerm *pOrTerm; /* A single subterm within the OR-clause */
+
+ pTerm = pLevel->plan.u.pTerm;
+ assert( pTerm!=0 );
+ assert( pTerm->eOperator==WO_OR );
+ assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
+ pOrWc = &pTerm->u.pOrInfo->wc;
+
+ regRowset = sqlite3GetTempReg(pParse);
+ sqlite3VdbeAddOp1(v, OP_Null, regRowset);
+ for(j=0, pOrTerm=pOrWc->a; j<pOrWc->nTerm; j++, pOrTerm++){
+ if( pOrTerm->leftCursor!=iCur ) continue;
+ /* fillRowSetFromIdx(pParse, regRowset, pTabItem, pOrTerm); */
+ }
+ regNextRowid = sqlite3GetTempReg(pParse);
+ sqlite3VdbeResolveLabel(v, addrCont);
+ addrCont =
+ sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowset, addrBrk, regNextRowid);
+ sqlite3VdbeAddOp2(v, OP_Seek, iCur, regNextRowid);
+ sqlite3ReleaseTempReg(pParse, regNextRowid);
+ pLevel->op = OP_Goto;
+ pLevel->p2 = addrCont;
+ }else{
+ /* Case 5: There is no usable index. We must do a complete
+ ** scan of the entire table.
+ */
+ assert( omitTable==0 );
+ assert( bRev==0 );
+ pLevel->op = OP_Next;
+ pLevel->p1 = iCur;
+ pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, OP_Rewind, iCur, addrBrk);
+ pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
+ }
+ notReady &= ~getMask(pWC->pMaskSet, iCur);
+
+ /* Insert code to test every subexpression that can be completely
+ ** computed using the current set of tables.
+ */
+ k = 0;
+ for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
+ Expr *pE;
+ testcase( pTerm->wtFlags & TERM_VIRTUAL );
+ testcase( pTerm->wtFlags & TERM_CODED );
+ if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+ if( (pTerm->prereqAll & notReady)!=0 ) continue;
+ pE = pTerm->pExpr;
+ assert( pE!=0 );
+ if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
+ continue;
+ }
+ pParse->disableColCache += k;
+ sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
+ pParse->disableColCache -= k;
+ k = 1;
+ pTerm->wtFlags |= TERM_CODED;
+ }
+
+ /* For a LEFT OUTER JOIN, generate code that will record the fact that
+ ** at least one row of the right table has matched the left table.
+ */
+ if( pLevel->iLeftJoin ){
+ pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);
+ sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
+ VdbeComment((v, "record LEFT JOIN hit"));
+ sqlite3ExprClearColumnCache(pParse, pLevel->iTabCur);
+ sqlite3ExprClearColumnCache(pParse, pLevel->iIdxCur);
+ for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){
+ testcase( pTerm->wtFlags & TERM_VIRTUAL );
+ testcase( pTerm->wtFlags & TERM_CODED );
+ if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+ if( (pTerm->prereqAll & notReady)!=0 ) continue;
+ assert( pTerm->pExpr );
+ sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
+ pTerm->wtFlags |= TERM_CODED;
+ }
+ }
+ return notReady;
+}
+
#if defined(SQLITE_TEST)
/*
** The following variable holds a text description of query plan generated
sqlite3DbFree(db, pInfo);
}
}
+ whereClauseClear(pWInfo->pWC);
sqlite3DbFree(db, pWInfo);
}
}
int i; /* Loop counter */
WhereInfo *pWInfo; /* Will become the return value of this function */
Vdbe *v = pParse->pVdbe; /* The virtual database engine */
- int addrBrk, addrCont = 0; /* Addresses used during code generation */
Bitmask notReady; /* Cursors that are not yet positioned */
- WhereTerm *pTerm; /* A single term in the WHERE clause */
- ExprMaskSet maskSet; /* The expression mask set */
- WhereClause wc; /* The WHERE clause is divided into these terms */
+ WhereMaskSet *pMaskSet; /* The expression mask set */
+ //WhereClause wc; /* The WHERE clause is divided into these terms */
+ WhereClause *pWC; /* Decomposition of the WHERE clause */
struct SrcList_item *pTabItem; /* A single entry from pTabList */
WhereLevel *pLevel; /* A single level in the pWInfo list */
int iFrom; /* First unused FROM clause element */
- int andFlags; /* AND-ed combination of all wc.a[].wtFlags */
+ int andFlags; /* AND-ed combination of all pWC->a[].wtFlags */
sqlite3 *db; /* Database connection */
ExprList *pOrderBy = 0;
pOrderBy = *ppOrderBy;
}
- /* Split the WHERE clause into separate subexpressions where each
- ** subexpression is separated by an AND operator.
- */
- initMaskSet(&maskSet);
- whereClauseInit(&wc, pParse, &maskSet);
- sqlite3ExprCodeConstants(pParse, pWhere);
- whereSplit(&wc, pWhere, TK_AND);
-
/* Allocate and initialize the WhereInfo structure that will become the
** return value.
*/
db = pParse->db;
pWInfo = sqlite3DbMallocZero(db,
- sizeof(WhereInfo) + pTabList->nSrc*sizeof(WhereLevel));
+ sizeof(WhereInfo)
+ + (pTabList->nSrc-1)*sizeof(WhereLevel)
+ + sizeof(WhereClause)
+ + sizeof(WhereMaskSet)
+ );
if( db->mallocFailed ){
goto whereBeginError;
}
pWInfo->pParse = pParse;
pWInfo->pTabList = pTabList;
pWInfo->iBreak = sqlite3VdbeMakeLabel(v);
+ pWInfo->pWC = pWC = (WhereClause*)&pWInfo->a[pWInfo->nLevel];
+ pMaskSet = (WhereMaskSet*)&pWC[1];
+ /* Split the WHERE clause into separate subexpressions where each
+ ** subexpression is separated by an AND operator.
+ */
+ initMaskSet(pMaskSet);
+ whereClauseInit(pWC, pParse, pMaskSet);
+ sqlite3ExprCodeConstants(pParse, pWhere);
+ whereSplit(pWC, pWhere, TK_AND);
+
/* Special case: a WHERE clause that is constant. Evaluate the
** expression and either jump over all of the code or fall thru.
*/
** for all tables to the left of a left join is important. Ticket #3015.
*/
for(i=0; i<pTabList->nSrc; i++){
- createMask(&maskSet, pTabList->a[i].iCursor);
+ createMask(pMaskSet, pTabList->a[i].iCursor);
}
#ifndef NDEBUG
{
Bitmask toTheLeft = 0;
for(i=0; i<pTabList->nSrc; i++){
- Bitmask m = getMask(&maskSet, pTabList->a[i].iCursor);
+ Bitmask m = getMask(pMaskSet, pTabList->a[i].iCursor);
assert( (m-1)==toTheLeft );
toTheLeft |= m;
}
** want to analyze these virtual terms, so start analyzing at the end
** and work forward so that the added virtual terms are never processed.
*/
- exprAnalyzeAll(pTabList, &wc);
+ exprAnalyzeAll(pTabList, pWC);
if( db->mallocFailed ){
goto whereBeginError;
}
** pWInfo->a[].iFrom Which term of the FROM clause is being coded
** pWInfo->a[].iTabCur The VDBE cursor for the database table
** pWInfo->a[].iIdxCur The VDBE cursor for the index
+ ** pWInfo->a[].pTerm When wsFlags==WO_OR, the OR-clause term
**
** This loop also figures out the nesting order of tables in the FROM
** clause.
andFlags = ~0;
WHERETRACE(("*** Optimizer Start ***\n"));
for(i=iFrom=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
+ WhereCost bestPlan; /* Most efficient plan seen so far */
Index *pIdx; /* Index for FROM table at pTabItem */
- int wsFlags; /* Flags describing scan strategy */
- int nEq; /* Number of == or IN constraints */
- double cost; /* The cost for pIdx */
int j; /* For looping over FROM tables */
- Index *pBest = 0; /* The best index seen so far */
- int bestWsFlags = 0; /* Flags associated with pBest */
- int bestNEq = 0; /* nEq associated with pBest */
- double lowestCost; /* Cost of the pBest */
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 *pIndex; /* Current virtual index */
- lowestCost = SQLITE_BIG_DBL;
+ memset(&bestPlan, 0, sizeof(bestPlan));
+ bestPlan.rCost = SQLITE_BIG_DBL;
for(j=iFrom, pTabItem=&pTabList->a[j]; j<pTabList->nSrc; j++, pTabItem++){
int doNotReorder; /* True if this table should not be reordered */
+ WhereCost sCost; /* Cost information from bestIndex() */
doNotReorder = (pTabItem->jointype & (JT_LEFT|JT_CROSS))!=0;
if( once && doNotReorder ) break;
- m = getMask(&maskSet, pTabItem->iCursor);
+ m = getMask(pMaskSet, pTabItem->iCursor);
if( (m & notReady)==0 ){
if( j==iFrom ) iFrom++;
continue;
assert( pTabItem->pTab );
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pTabItem->pTab) ){
+ sqlite3_index_info *pVtabIdx; /* Current virtual index */
sqlite3_index_info **ppIdxInfo = &pWInfo->a[j].pIdxInfo;
- cost = bestVirtualIndex(pParse, &wc, pTabItem, notReady,
- ppOrderBy ? *ppOrderBy : 0, i==0,
- ppIdxInfo);
- wsFlags = WHERE_VIRTUALTABLE;
- pIndex = *ppIdxInfo;
- if( pIndex && pIndex->orderByConsumed ){
- wsFlags = WHERE_VIRTUALTABLE | WHERE_ORDERBY;
+ sCost.rCost = bestVirtualIndex(pParse, pWC, pTabItem, notReady,
+ ppOrderBy ? *ppOrderBy : 0, i==0,
+ ppIdxInfo);
+ sCost.plan.wsFlags = WHERE_VIRTUALTABLE;
+ sCost.plan.u.pVtabIdx = pVtabIdx = *ppIdxInfo;
+ if( pVtabIdx && pVtabIdx->orderByConsumed ){
+ sCost.plan.wsFlags = WHERE_VIRTUALTABLE | WHERE_ORDERBY;
}
- pIdx = 0;
- nEq = 0;
- if( (SQLITE_BIG_DBL/2.0)<cost ){
+ sCost.plan.nEq = 0;
+ if( (SQLITE_BIG_DBL/2.0)<sCost.rCost ){
/* The cost is not allowed to be larger than SQLITE_BIG_DBL (the
** inital value of lowestCost in this loop. If it is, then
- ** the (cost<lowestCost) test below will never be true and
- ** pLevel->pBestIdx never set.
+ ** the (cost<lowestCost) test below will never be true.
*/
- cost = (SQLITE_BIG_DBL/2.0);
+ sCost.rCost = (SQLITE_BIG_DBL/2.0);
}
}else
#endif
{
- cost = bestIndex(pParse, &wc, pTabItem, notReady,
- (i==0 && ppOrderBy) ? *ppOrderBy : 0,
- &pIdx, &wsFlags, &nEq);
- pIndex = 0;
+ bestIndex(pParse, pWC, pTabItem, notReady,
+ (i==0 && ppOrderBy) ? *ppOrderBy : 0, &sCost);
}
- if( cost<lowestCost ){
+ if( sCost.rCost<bestPlan.rCost ){
once = 1;
- lowestCost = cost;
- pBest = pIdx;
- bestWsFlags = wsFlags;
- bestNEq = nEq;
+ bestPlan = sCost;
bestJ = j;
- pLevel->pBestIdx = pIndex;
}
if( doNotReorder ) break;
}
WHERETRACE(("*** Optimizer selects table %d for loop %d\n", bestJ,
pLevel-pWInfo->a));
- if( (bestWsFlags & WHERE_ORDERBY)!=0 ){
+ if( (bestPlan.plan.wsFlags & WHERE_ORDERBY)!=0 ){
*ppOrderBy = 0;
}
- andFlags &= bestWsFlags;
- pLevel->wsFlags = bestWsFlags;
- pLevel->pIdx = pBest;
- pLevel->nEq = bestNEq;
- pLevel->aInLoop = 0;
- pLevel->nIn = 0;
- if( pBest ){
+ andFlags &= bestPlan.plan.wsFlags;
+ pLevel->plan = bestPlan.plan;
+ if( bestPlan.plan.wsFlags & WHERE_INDEXED ){
pLevel->iIdxCur = pParse->nTab++;
}else{
pLevel->iIdxCur = -1;
}
- notReady &= ~getMask(&maskSet, pTabList->a[bestJ].iCursor);
+ notReady &= ~getMask(pMaskSet, pTabList->a[bestJ].iCursor);
pLevel->iFrom = bestJ;
/* Check that if the table scanned by this loop iteration had an
** Return an error.
*/
pIdx = pTabList->a[bestJ].pIndex;
- assert( !pIdx || !pBest || pIdx==pBest );
- if( pIdx && pBest!=pIdx ){
+ assert( !pIdx
+ || (bestPlan.plan.wsFlags&WHERE_INDEXED)==0
+ || pIdx==bestPlan.plan.u.pIdx );
+ if( pIdx
+ && ((bestPlan.plan.wsFlags & WHERE_INDEXED)==0
+ || bestPlan.plan.u.pIdx!=pIdx)
+ ){
sqlite3ErrorMsg(pParse, "cannot use index: %s", pIdx->zName);
goto whereBeginError;
}
assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 && (andFlags & WHERE_UNIQUE)!=0 ){
pWInfo->okOnePass = 1;
- pWInfo->a[0].wsFlags &= ~WHERE_IDX_ONLY;
+ pWInfo->a[0].plan.wsFlags &= ~WHERE_IDX_ONLY;
}
/* Open all tables in the pTabList and any indices selected for
sqlite3CodeVerifySchema(pParse, -1); /* Insert the cookie verifier Goto */
for(i=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
Table *pTab; /* Table to open */
- Index *pIx; /* Index used to access pTab (if any) */
int iDb; /* Index of database containing table/index */
- int iIdxCur = pLevel->iIdxCur;
#ifndef SQLITE_OMIT_EXPLAIN
if( pParse->explain==2 ){
if( pItem->zAlias ){
zMsg = sqlite3MAppendf(db, zMsg, "%s AS %s", zMsg, pItem->zAlias);
}
- if( (pIx = pLevel->pIdx)!=0 ){
- zMsg = sqlite3MAppendf(db, zMsg, "%s WITH INDEX %s", zMsg, pIx->zName);
- }else if( pLevel->wsFlags & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){
+ if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){
+ zMsg = sqlite3MAppendf(db, zMsg, "%s WITH INDEX %s",
+ zMsg, pLevel->plan.u.pIdx->zName);
+ }else if( pLevel->plan.wsFlags & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){
zMsg = sqlite3MAppendf(db, zMsg, "%s USING PRIMARY KEY", zMsg);
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
- else if( pLevel->pBestIdx ){
- sqlite3_index_info *pBestIdx = pLevel->pBestIdx;
+ else if( (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){
+ sqlite3_index_info *pVtabIdx = pLevel->plan.u.pVtabIdx;
zMsg = sqlite3MAppendf(db, zMsg, "%s VIRTUAL TABLE INDEX %d:%s", zMsg,
- pBestIdx->idxNum, pBestIdx->idxStr);
+ pVtabIdx->idxNum, pVtabIdx->idxStr);
}
#endif
- if( pLevel->wsFlags & WHERE_ORDERBY ){
+ if( pLevel->plan.wsFlags & WHERE_ORDERBY ){
zMsg = sqlite3MAppendf(db, zMsg, "%s ORDER BY", zMsg);
}
sqlite3VdbeAddOp4(v, OP_Explain, i, pLevel->iFrom, 0, zMsg, P4_DYNAMIC);
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
if( (pTab->tabFlags & TF_Ephemeral)!=0 || pTab->pSelect ) continue;
#ifndef SQLITE_OMIT_VIRTUALTABLE
- if( pLevel->pBestIdx ){
+ if( (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){
int iCur = pTabItem->iCursor;
sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0,
(const char*)pTab->pVtab, P4_VTAB);
}else
#endif
- if( (pLevel->wsFlags & WHERE_IDX_ONLY)==0 ){
+ if( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0 ){
int op = pWInfo->okOnePass ? OP_OpenWrite : OP_OpenRead;
sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);
if( !pWInfo->okOnePass && pTab->nCol<BMS ){
sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
}
pLevel->iTabCur = pTabItem->iCursor;
- if( (pIx = pLevel->pIdx)!=0 ){
+ if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){
+ Index *pIx = pLevel->plan.u.pIdx;
KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIx);
+ int iIdxCur = pLevel->iIdxCur;
assert( pIx->pSchema==pTab->pSchema );
+ assert( iIdxCur>=0 );
sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pIx->nColumn+1);
sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIx->tnum, iDb,
(char*)pKey, P4_KEYINFO_HANDOFF);
** program.
*/
notReady = ~(Bitmask)0;
- for(i=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
- int j, k;
- int iCur = pTabItem->iCursor; /* The VDBE cursor for the table */
- Index *pIdx; /* The index we will be using */
- int addrNxt; /* Where to jump to continue with the next IN case */
- int iIdxCur; /* The VDBE cursor for the index */
- int omitTable; /* True if we use the index only */
- int bRev; /* True if we need to scan in reverse order */
-
- pTabItem = &pTabList->a[pLevel->iFrom];
- iCur = pTabItem->iCursor;
- pIdx = pLevel->pIdx;
- iIdxCur = pLevel->iIdxCur;
- bRev = (pLevel->wsFlags & WHERE_REVERSE)!=0;
- omitTable = (pLevel->wsFlags & WHERE_IDX_ONLY)!=0;
-
- /* Create labels for the "break" and "continue" instructions
- ** for the current loop. Jump to addrBrk to break out of a loop.
- ** Jump to cont to go immediately to the next iteration of the
- ** loop.
- **
- ** When there is an IN operator, we also have a "addrNxt" label that
- ** means to continue with the next IN value combination. When
- ** there are no IN operators in the constraints, the "addrNxt" label
- ** is the same as "addrBrk".
- */
- addrBrk = pLevel->addrBrk = pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
- addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(v);
-
- /* If this is the right table of a LEFT OUTER JOIN, allocate and
- ** initialize a memory cell that records if this table matches any
- ** row of the left table of the join.
- */
- if( pLevel->iFrom>0 && (pTabItem[0].jointype & JT_LEFT)!=0 ){
- pLevel->iLeftJoin = ++pParse->nMem;
- sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
- VdbeComment((v, "init LEFT JOIN no-match flag"));
- }
-
-#ifndef SQLITE_OMIT_VIRTUALTABLE
- if( pLevel->pBestIdx ){
- /* Case 0: The table is a virtual-table. Use the VFilter and VNext
- ** to access the data.
- */
- int iReg; /* P3 Value for OP_VFilter */
- sqlite3_index_info *pBestIdx = pLevel->pBestIdx;
- int nConstraint = pBestIdx->nConstraint;
- struct sqlite3_index_constraint_usage *aUsage =
- pBestIdx->aConstraintUsage;
- const struct sqlite3_index_constraint *aConstraint =
- pBestIdx->aConstraint;
-
- iReg = sqlite3GetTempRange(pParse, nConstraint+2);
- pParse->disableColCache++;
- for(j=1; j<=nConstraint; j++){
- for(k=0; k<nConstraint; k++){
- if( aUsage[k].argvIndex==j ){
- int iTerm = aConstraint[k].iTermOffset;
- assert( pParse->disableColCache );
- sqlite3ExprCode(pParse, wc.a[iTerm].pExpr->pRight, iReg+j+1);
- break;
- }
- }
- if( k==nConstraint ) break;
- }
- assert( pParse->disableColCache );
- pParse->disableColCache--;
- sqlite3VdbeAddOp2(v, OP_Integer, pBestIdx->idxNum, iReg);
- sqlite3VdbeAddOp2(v, OP_Integer, j-1, iReg+1);
- sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrBrk, iReg, pBestIdx->idxStr,
- pBestIdx->needToFreeIdxStr ? P4_MPRINTF : P4_STATIC);
- sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
- pBestIdx->needToFreeIdxStr = 0;
- for(j=0; j<nConstraint; j++){
- if( aUsage[j].omit ){
- int iTerm = aConstraint[j].iTermOffset;
- disableTerm(pLevel, &wc.a[iTerm]);
- }
- }
- pLevel->op = OP_VNext;
- pLevel->p1 = iCur;
- pLevel->p2 = sqlite3VdbeCurrentAddr(v);
- }else
-#endif /* SQLITE_OMIT_VIRTUALTABLE */
-
- if( pLevel->wsFlags & WHERE_ROWID_EQ ){
- /* Case 1: We can directly reference a single row using an
- ** equality comparison against the ROWID field. Or
- ** we reference multiple rows using a "rowid IN (...)"
- ** construct.
- */
- int r1;
- int rtmp = sqlite3GetTempReg(pParse);
- pTerm = findTerm(&wc, iCur, -1, notReady, WO_EQ|WO_IN, 0);
- assert( pTerm!=0 );
- assert( pTerm->pExpr!=0 );
- assert( pTerm->leftCursor==iCur );
- assert( omitTable==0 );
- r1 = codeEqualityTerm(pParse, pTerm, pLevel, rtmp);
- addrNxt = pLevel->addrNxt;
- sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, addrNxt);
- sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addrNxt, r1);
- sqlite3ReleaseTempReg(pParse, rtmp);
- VdbeComment((v, "pk"));
- pLevel->op = OP_Noop;
- }else if( pLevel->wsFlags & WHERE_ROWID_RANGE ){
- /* Case 2: We have an inequality comparison against the ROWID field.
- */
- int testOp = OP_Noop;
- int start;
- int memEndValue = 0;
- WhereTerm *pStart, *pEnd;
-
- assert( omitTable==0 );
- pStart = findTerm(&wc, iCur, -1, notReady, WO_GT|WO_GE, 0);
- pEnd = findTerm(&wc, iCur, -1, notReady, WO_LT|WO_LE, 0);
- if( bRev ){
- pTerm = pStart;
- pStart = pEnd;
- pEnd = pTerm;
- }
- if( pStart ){
- Expr *pX; /* The expression that defines the start bound */
- int r1, rTemp; /* Registers for holding the start boundary */
-
- /* The following constant maps TK_xx codes into corresponding
- ** seek opcodes. It depends on a particular ordering of TK_xx
- */
- const u8 aMoveOp[] = {
- /* TK_GT */ OP_SeekGt,
- /* TK_LE */ OP_SeekLe,
- /* TK_LT */ OP_SeekLt,
- /* TK_GE */ OP_SeekGe
- };
- assert( TK_LE==TK_GT+1 ); /* Make sure the ordering.. */
- assert( TK_LT==TK_GT+2 ); /* ... of the TK_xx values... */
- assert( TK_GE==TK_GT+3 ); /* ... is correcct. */
-
- pX = pStart->pExpr;
- assert( pX!=0 );
- assert( pStart->leftCursor==iCur );
- r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
- sqlite3VdbeAddOp3(v, aMoveOp[pX->op-TK_GT], iCur, addrBrk, r1);
- VdbeComment((v, "pk"));
- sqlite3ExprCacheAffinityChange(pParse, r1, 1);
- sqlite3ReleaseTempReg(pParse, rTemp);
- disableTerm(pLevel, pStart);
- }else{
- sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrBrk);
- }
- if( pEnd ){
- Expr *pX;
- pX = pEnd->pExpr;
- assert( pX!=0 );
- assert( pEnd->leftCursor==iCur );
- memEndValue = ++pParse->nMem;
- sqlite3ExprCode(pParse, pX->pRight, memEndValue);
- if( pX->op==TK_LT || pX->op==TK_GT ){
- testOp = bRev ? OP_Le : OP_Ge;
- }else{
- testOp = bRev ? OP_Lt : OP_Gt;
- }
- disableTerm(pLevel, pEnd);
- }
- start = sqlite3VdbeCurrentAddr(v);
- pLevel->op = bRev ? OP_Prev : OP_Next;
- pLevel->p1 = iCur;
- pLevel->p2 = start;
- if( testOp!=OP_Noop ){
- int r1 = sqlite3GetTempReg(pParse);
- sqlite3VdbeAddOp2(v, OP_Rowid, iCur, r1);
- sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, r1);
- sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
- sqlite3ReleaseTempReg(pParse, r1);
- }
- }else if( pLevel->wsFlags & (WHERE_COLUMN_RANGE|WHERE_COLUMN_EQ) ){
- /* Case 3: A scan using an index.
- **
- ** The WHERE clause may contain zero or more equality
- ** terms ("==" or "IN" operators) that refer to the N
- ** left-most columns of the index. It may also contain
- ** inequality constraints (>, <, >= or <=) on the indexed
- ** column that immediately follows the N equalities. Only
- ** the right-most column can be an inequality - the rest must
- ** use the "==" and "IN" operators. For example, if the
- ** index is on (x,y,z), then the following clauses are all
- ** optimized:
- **
- ** x=5
- ** x=5 AND y=10
- ** x=5 AND y<10
- ** x=5 AND y>5 AND y<10
- ** x=5 AND y=5 AND z<=10
- **
- ** The z<10 term of the following cannot be used, only
- ** the x=5 term:
- **
- ** x=5 AND z<10
- **
- ** N may be zero if there are inequality constraints.
- ** If there are no inequality constraints, then N is at
- ** least one.
- **
- ** This case is also used when there are no WHERE clause
- ** constraints but an index is selected anyway, in order
- ** to force the output order to conform to an ORDER BY.
- */
- int aStartOp[] = {
- 0,
- 0,
- OP_Rewind, /* 2: (!start_constraints && startEq && !bRev) */
- OP_Last, /* 3: (!start_constraints && startEq && bRev) */
- OP_SeekGt, /* 4: (start_constraints && !startEq && !bRev) */
- OP_SeekLt, /* 5: (start_constraints && !startEq && bRev) */
- OP_SeekGe, /* 6: (start_constraints && startEq && !bRev) */
- OP_SeekLe /* 7: (start_constraints && startEq && bRev) */
- };
- int aEndOp[] = {
- OP_Noop, /* 0: (!end_constraints) */
- OP_IdxGE, /* 1: (end_constraints && !bRev) */
- OP_IdxLT /* 2: (end_constraints && bRev) */
- };
- int nEq = pLevel->nEq;
- int isMinQuery = 0; /* If this is an optimized SELECT min(x).. */
- int regBase; /* Base register holding constraint values */
- int r1; /* Temp register */
- WhereTerm *pRangeStart = 0; /* Inequality constraint at range start */
- WhereTerm *pRangeEnd = 0; /* Inequality constraint at range end */
- int startEq; /* True if range start uses ==, >= or <= */
- int endEq; /* True if range end uses ==, >= or <= */
- int start_constraints; /* Start of range is constrained */
- int nConstraint; /* Number of constraint terms */
- int op;
-
- k = pIdx->aiColumn[nEq]; /* Column for inequality constraints */
-
- /* Generate code to evaluate all constraint terms using == or IN
- ** and store the values of those terms in an array of registers
- ** starting at regBase.
- */
- regBase = codeAllEqualityTerms(pParse, pLevel, &wc, notReady, 2);
- addrNxt = pLevel->addrNxt;
-
- /* If this loop satisfies a sort order (pOrderBy) request that
- ** was passed to this function to implement a "SELECT min(x) ..."
- ** query, then the caller will only allow the loop to run for
- ** a single iteration. This means that the first row returned
- ** should not have a NULL value stored in 'x'. If column 'x' is
- ** the first one after the nEq equality constraints in the index,
- ** this requires some special handling.
- */
- if( (wctrlFlags&WHERE_ORDERBY_MIN)!=0
- && (pLevel->wsFlags&WHERE_ORDERBY)
- && (pIdx->nColumn>nEq)
- ){
- assert( pOrderBy->nExpr==1 );
- assert( pOrderBy->a[0].pExpr->iColumn==pIdx->aiColumn[nEq] );
- isMinQuery = 1;
- }
-
- /* Find any inequality constraint terms for the start and end
- ** of the range.
- */
- if( pLevel->wsFlags & WHERE_TOP_LIMIT ){
- pRangeEnd = findTerm(&wc, iCur, k, notReady, (WO_LT|WO_LE), pIdx);
- }
- if( pLevel->wsFlags & WHERE_BTM_LIMIT ){
- pRangeStart = findTerm(&wc, iCur, k, notReady, (WO_GT|WO_GE), pIdx);
- }
-
- /* If we are doing a reverse order scan on an ascending index, or
- ** a forward order scan on a descending index, interchange the
- ** start and end terms (pRangeStart and pRangeEnd).
- */
- if( bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC) ){
- SWAP(WhereTerm *, pRangeEnd, pRangeStart);
- }
-
- testcase( pRangeStart && pRangeStart->eOperator & WO_LE );
- testcase( pRangeStart && pRangeStart->eOperator & WO_GE );
- testcase( pRangeEnd && pRangeEnd->eOperator & WO_LE );
- testcase( pRangeEnd && pRangeEnd->eOperator & WO_GE );
- startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
- endEq = !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
- start_constraints = pRangeStart || nEq>0;
-
- /* Seek the index cursor to the start of the range. */
- nConstraint = nEq;
- if( pRangeStart ){
- int dcc = pParse->disableColCache;
- if( pRangeEnd ){
- pParse->disableColCache++;
- }
- sqlite3ExprCode(pParse, pRangeStart->pExpr->pRight, regBase+nEq);
- pParse->disableColCache = dcc;
- sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
- nConstraint++;
- }else if( isMinQuery ){
- sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
- nConstraint++;
- startEq = 0;
- start_constraints = 1;
- }
- codeApplyAffinity(pParse, regBase, nConstraint, pIdx);
- op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
- assert( op!=0 );
- testcase( op==OP_Rewind );
- testcase( op==OP_Last );
- testcase( op==OP_SeekGt );
- testcase( op==OP_SeekGe );
- testcase( op==OP_SeekLe );
- testcase( op==OP_SeekLt );
- sqlite3VdbeAddOp4(v, op, iIdxCur, addrNxt, regBase,
- SQLITE_INT_TO_PTR(nConstraint), P4_INT32);
-
- /* Load the value for the inequality constraint at the end of the
- ** range (if any).
- */
- nConstraint = nEq;
- if( pRangeEnd ){
- sqlite3ExprCode(pParse, pRangeEnd->pExpr->pRight, regBase+nEq);
- sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
- codeApplyAffinity(pParse, regBase, nEq+1, pIdx);
- nConstraint++;
- }
-
- /* Top of the loop body */
- pLevel->p2 = sqlite3VdbeCurrentAddr(v);
-
- /* Check if the index cursor is past the end of the range. */
- op = aEndOp[(pRangeEnd || nEq) * (1 + bRev)];
- testcase( op==OP_Noop );
- testcase( op==OP_IdxGE );
- testcase( op==OP_IdxLT );
- sqlite3VdbeAddOp4(v, op, iIdxCur, addrNxt, regBase,
- SQLITE_INT_TO_PTR(nConstraint), P4_INT32);
- sqlite3VdbeChangeP5(v, endEq!=bRev ?1:0);
-
- /* If there are inequality constraints, check that the value
- ** of the table column that the inequality contrains is not NULL.
- ** If it is, jump to the next iteration of the loop.
- */
- r1 = sqlite3GetTempReg(pParse);
- testcase( pLevel->wsFlags & WHERE_BTM_LIMIT );
- testcase( pLevel->wsFlags & WHERE_TOP_LIMIT );
- if( pLevel->wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT) ){
- sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, nEq, r1);
- sqlite3VdbeAddOp2(v, OP_IsNull, r1, addrCont);
- }
-
- /* Seek the table cursor, if required */
- if( !omitTable ){
- sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, r1);
- sqlite3VdbeAddOp2(v, OP_Seek, iCur, r1); /* Deferred seek */
- }
- sqlite3ReleaseTempReg(pParse, r1);
-
- /* Record the instruction used to terminate the loop. Disable
- ** WHERE clause terms made redundant by the index range scan.
- */
- pLevel->op = bRev ? OP_Prev : OP_Next;
- pLevel->p1 = iIdxCur;
- disableTerm(pLevel, pRangeStart);
- disableTerm(pLevel, pRangeEnd);
- }else if( pLevel->wsFlags & WHERE_MULTI_OR ){
- /* Case 4: Two or more separately indexed terms connected by OR
- **
- ** Example:
- **
- ** CREATE TABLE t1(a,b,c,d);
- ** CREATE INDEX i1 ON t1(a);
- ** CREATE INDEX i2 ON t1(b);
- ** CREATE INDEX i3 ON t1(c);
- **
- ** SELECT * FROM t1 WHERE a=5 OR b=7 OR (c=11 AND d=13)
- **
- ** In the example, there are three indexed terms connected by OR.
- ** The top of the loop is constructed by creating a RowSet object
- ** and populating it. Then looping over elements of the rowset.
- **
- ** Null 1
- ** # fill RowSet 1 with entries where a=5 using i1
- ** # fill Rowset 1 with entries where b=7 using i2
- ** # fill Rowset 1 with entries where c=11 and d=13 i3 and t1
- ** A: RowSetRead 1, B, 2
- ** Seek i, 2
- **
- ** The bottom of the loop looks like this:
- **
- ** C: Goto 0, A
- ** B:
- */
- }else{
- /* Case 5: There is no usable index. We must do a complete
- ** scan of the entire table.
- */
- assert( omitTable==0 );
- assert( bRev==0 );
- pLevel->op = OP_Next;
- pLevel->p1 = iCur;
- pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, OP_Rewind, iCur, addrBrk);
- pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
- }
- notReady &= ~getMask(&maskSet, iCur);
-
- /* Insert code to test every subexpression that can be completely
- ** computed using the current set of tables.
- */
- k = 0;
- for(pTerm=wc.a, j=wc.nTerm; j>0; j--, pTerm++){
- Expr *pE;
- testcase( pTerm->wtFlags & TERM_VIRTUAL );
- testcase( pTerm->wtFlags & TERM_CODED );
- if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
- if( (pTerm->prereqAll & notReady)!=0 ) continue;
- pE = pTerm->pExpr;
- assert( pE!=0 );
- if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
- continue;
- }
- pParse->disableColCache += k;
- sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
- pParse->disableColCache -= k;
- k = 1;
- pTerm->wtFlags |= TERM_CODED;
- }
-
- /* For a LEFT OUTER JOIN, generate code that will record the fact that
- ** at least one row of the right table has matched the left table.
- */
- if( pLevel->iLeftJoin ){
- pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);
- sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
- VdbeComment((v, "record LEFT JOIN hit"));
- sqlite3ExprClearColumnCache(pParse, pLevel->iTabCur);
- sqlite3ExprClearColumnCache(pParse, pLevel->iIdxCur);
- for(pTerm=wc.a, j=0; j<wc.nTerm; j++, pTerm++){
- testcase( pTerm->wtFlags & TERM_VIRTUAL );
- testcase( pTerm->wtFlags & TERM_CODED );
- if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
- if( (pTerm->prereqAll & notReady)!=0 ) continue;
- assert( pTerm->pExpr );
- sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
- pTerm->wtFlags |= TERM_CODED;
- }
- }
+ for(i=0; i<pTabList->nSrc; i++){
+ notReady = codeOneLoopStart(pWInfo, i, wctrlFlags, notReady);
}
+ pWInfo->iContinue = pWInfo->a[i-1].addrCont;
#ifdef SQLITE_TEST /* For testing and debugging use only */
/* Record in the query plan information about the current table
if( z==0 ) z = pTabItem->pTab->zName;
n = sqlite3Strlen30(z);
if( n+nQPlan < sizeof(sqlite3_query_plan)-10 ){
- if( pLevel->wsFlags & WHERE_IDX_ONLY ){
+ if( pLevel->plan.wsFlags & WHERE_IDX_ONLY ){
memcpy(&sqlite3_query_plan[nQPlan], "{}", 2);
nQPlan += 2;
}else{
}
sqlite3_query_plan[nQPlan++] = ' ';
}
- testcase( pLevel->wsFlags & WHERE_ROWID_EQ );
- testcase( pLevel->wsFlags & WHERE_ROWID_RANGE );
- if( pLevel->wsFlags & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){
+ testcase( pLevel->plan.wsFlags & WHERE_ROWID_EQ );
+ testcase( pLevel->plan.wsFlags & WHERE_ROWID_RANGE );
+ if( pLevel->plan.wsFlags & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){
memcpy(&sqlite3_query_plan[nQPlan], "* ", 2);
nQPlan += 2;
- }else if( pLevel->pIdx==0 ){
- memcpy(&sqlite3_query_plan[nQPlan], "{} ", 3);
- nQPlan += 3;
- }else{
- n = sqlite3Strlen30(pLevel->pIdx->zName);
+ }else if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){
+ n = sqlite3Strlen30(pLevel->plan.u.pIdx->zName);
if( n+nQPlan < sizeof(sqlite3_query_plan)-2 ){
- memcpy(&sqlite3_query_plan[nQPlan], pLevel->pIdx->zName, n);
+ memcpy(&sqlite3_query_plan[nQPlan], pLevel->plan.u.pIdx->zName, n);
nQPlan += n;
sqlite3_query_plan[nQPlan++] = ' ';
}
+ }else{
+ memcpy(&sqlite3_query_plan[nQPlan], "{} ", 3);
+ nQPlan += 3;
}
}
while( nQPlan>0 && sqlite3_query_plan[nQPlan-1]==' ' ){
/* Record the continuation address in the WhereInfo structure. Then
** clean up and return.
*/
- pWInfo->iContinue = addrCont;
- whereClauseClear(&wc);
return pWInfo;
/* Jump here if malloc fails */
whereBeginError:
- whereClauseClear(&wc);
whereInfoFree(db, pWInfo);
return 0;
}
sqlite3VdbeAddOp2(v, pLevel->op, pLevel->p1, pLevel->p2);
sqlite3VdbeChangeP5(v, pLevel->p5);
}
- if( pLevel->nIn ){
+ if( pLevel->plan.wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){
struct InLoop *pIn;
int j;
sqlite3VdbeResolveLabel(v, pLevel->addrNxt);
- for(j=pLevel->nIn, pIn=&pLevel->aInLoop[j-1]; j>0; j--, pIn--){
+ for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){
sqlite3VdbeJumpHere(v, pIn->addrInTop+1);
sqlite3VdbeAddOp2(v, OP_Next, pIn->iCur, pIn->addrInTop);
sqlite3VdbeJumpHere(v, pIn->addrInTop-1);
}
- sqlite3DbFree(db, pLevel->aInLoop);
+ sqlite3DbFree(db, pLevel->u.in.aInLoop);
}
sqlite3VdbeResolveLabel(v, pLevel->addrBrk);
if( pLevel->iLeftJoin ){
Table *pTab = pTabItem->pTab;
assert( pTab!=0 );
if( (pTab->tabFlags & TF_Ephemeral)!=0 || pTab->pSelect ) continue;
- if( !pWInfo->okOnePass && (pLevel->wsFlags & WHERE_IDX_ONLY)==0 ){
+ if( !pWInfo->okOnePass && (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0 ){
sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);
}
- if( pLevel->pIdx!=0 ){
+ if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){
sqlite3VdbeAddOp1(v, OP_Close, pLevel->iIdxCur);
}
** that reference the table and converts them into opcodes that
** reference the index.
*/
- if( pLevel->pIdx ){
+ if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){
int k, j, last;
VdbeOp *pOp;
- Index *pIdx = pLevel->pIdx;
- int useIndexOnly = pLevel->wsFlags & WHERE_IDX_ONLY;
+ Index *pIdx = pLevel->plan.u.pIdx;
+ int useIndexOnly = pLevel->plan.wsFlags & WHERE_IDX_ONLY;
assert( pIdx!=0 );
pOp = sqlite3VdbeGetOp(v, pWInfo->iTop);
projects / thirdparty / sqlite.git / commitdiff
