int nKey; /* Number of PK columns for table pTab (>=1) */
} aDefer[4];
#endif
+ struct RowLoadInfo *pDeferredRowLoad; /* Deferred row loading info or NULL */
};
#define SORTFLAG_UseSorter 0x01 /* Use SorterOpen instead of OpenEphemeral */
int nExtra /* Add this many extra columns to the end */
);
+/*
+** An instance of this object holds information (beyond pParse and pSelect)
+** needed to load the next result row that is to be added to the sorter.
+*/
+typedef struct RowLoadInfo RowLoadInfo;
+struct RowLoadInfo {
+ int regResult; /* Store results in array of registers here */
+ u8 ecelFlags; /* Flag argument to ExprCodeExprList() */
+#ifdef SQLITE_ENABLE_SORTER_REFERENCES
+ ExprList *pExtra; /* Extra columns needed by sorter refs */
+ int regExtraResult; /* Where to load the extra columns */
+#endif
+};
+
+/*
+** This routine does the work of loading query data into an array of
+** registers so that it can be added to the sorter.
+*/
+static void innerLoopLoadRow(
+ Parse *pParse, /* Statement under construction */
+ Select *pSelect, /* The query being coded */
+ RowLoadInfo *pInfo /* Info needed to complete the row load */
+){
+ sqlite3ExprCodeExprList(pParse, pSelect->pEList, pInfo->regResult,
+ 0, pInfo->ecelFlags);
+#ifdef SQLITE_ENABLE_SORTER_REFERENCES
+ if( pInfo->pExtra ){
+ sqlite3ExprCodeExprList(pParse, pInfo->pExtra, pInfo->regExtraResult, 0, 0);
+ sqlite3ExprListDelete(pParse->db, pInfo->pExtra);
+ }
+#endif
+}
+
+/*
+** Code the OP_MakeRecord instruction that generates the entry to be
+** added into the sorter.
+**
+** Return the register in which the result is stored.
+*/
+static int makeSorterRecord(
+ Parse *pParse,
+ SortCtx *pSort,
+ Select *pSelect,
+ int regBase,
+ int nBase
+){
+ int nOBSat = pSort->nOBSat;
+ Vdbe *v = pParse->pVdbe;
+ int regOut = ++pParse->nMem;
+ if( pSort->pDeferredRowLoad ){
+ innerLoopLoadRow(pParse, pSelect, pSort->pDeferredRowLoad);
+ }
+ sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat, regOut);
+ return regOut;
+}
+
/*
** Generate code that will push the record in registers regData
** through regData+nData-1 onto the sorter.
Select *pSelect, /* The whole SELECT statement */
int regData, /* First register holding data to be sorted */
int regOrigData, /* First register holding data before packing */
- int nData, /* Number of elements in the data array */
+ int nData, /* Number of elements in the regData data array */
int nPrefixReg /* No. of reg prior to regData available for use */
){
Vdbe *v = pParse->pVdbe; /* Stmt under construction */
int nExpr = pSort->pOrderBy->nExpr; /* No. of ORDER BY terms */
int nBase = nExpr + bSeq + nData; /* Fields in sorter record */
int regBase; /* Regs for sorter record */
- int regRecord = ++pParse->nMem; /* Assembled sorter record */
+ int regRecord = 0; /* Assembled sorter record */
int nOBSat = pSort->nOBSat; /* ORDER BY terms to skip */
int op; /* Opcode to add sorter record to sorter */
int iLimit; /* LIMIT counter */
+ int iSkip = 0; /* End of the sorter insert loop */
assert( bSeq==0 || bSeq==1 );
+
+ /* Three cases:
+ ** (1) The data to be sorted has already been packed into a Record
+ ** by a prior OP_MakeRecord. In this case nData==1 and regData
+ ** will be completely unrelated to regOrigData.
+ ** (2) All output columns are included in the sort record. In that
+ ** case regData==regOrigData.
+ ** (3) Some output columns are omitted from the sort record due to
+ ** the SQLITE_ENABLE_SORTER_REFERENCE optimization, or due to the
+ ** SQLITE_ECEL_OMITREF optimization. In that case, regOrigData==0
+ ** to prevent this routine from trying to copy values that might
+ ** not exist.
+ */
assert( nData==1 || regData==regOrigData || regOrigData==0 );
+
if( nPrefixReg ){
assert( nPrefixReg==nExpr+bSeq );
- regBase = regData - nExpr - bSeq;
+ regBase = regData - nPrefixReg;
}else{
regBase = pParse->nMem + 1;
pParse->nMem += nBase;
int nKey; /* Number of sorting key columns, including OP_Sequence */
KeyInfo *pKI; /* Original KeyInfo on the sorter table */
- sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat,regRecord);
+ regRecord = makeSorterRecord(pParse, pSort, pSelect, regBase, nBase);
regPrevKey = pParse->nMem+1;
pParse->nMem += pSort->nOBSat;
nKey = nExpr - pSort->nOBSat + bSeq;
** of the outer loop.
*/
int iCsr = pSort->iECursor;
- int iJmp = sqlite3VdbeCurrentAddr(v)+5+(nOBSat<=0)+pSort->bOrderedInnerLoop;
- assert( pSort->bOrderedInnerLoop==0 || pSort->bOrderedInnerLoop==1 );
sqlite3VdbeAddOp2(v, OP_IfNotZero, iLimit, sqlite3VdbeCurrentAddr(v)+4);
VdbeCoverage(v);
sqlite3VdbeAddOp2(v, OP_Last, iCsr, 0);
- sqlite3VdbeAddOp4Int(v, OP_IdxLE, iCsr, iJmp, regBase+nOBSat, nExpr-nOBSat);
+ iSkip = sqlite3VdbeAddOp4Int(v, OP_IdxLE,
+ iCsr, 0, regBase+nOBSat, nExpr-nOBSat);
VdbeCoverage(v);
sqlite3VdbeAddOp1(v, OP_Delete, iCsr);
}
- if( nOBSat<=0 ){
- sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat,regRecord);
+ if( regRecord==0 ){
+ regRecord = makeSorterRecord(pParse, pSort, pSelect, regBase, nBase);
}
if( pSort->sortFlags & SORTFLAG_UseSorter ){
op = OP_SorterInsert;
}
sqlite3VdbeAddOp4Int(v, op, pSort->iECursor, regRecord,
regBase+nOBSat, nBase-nOBSat);
+ if( iSkip ){
+ assert( pSort->bOrderedInnerLoop==0 || pSort->bOrderedInnerLoop==1 );
+ sqlite3VdbeChangeP2(v, iSkip,
+ sqlite3VdbeCurrentAddr(v) + pSort->bOrderedInnerLoop);
+ }
}
/*
Table *pTab = pExpr->pTab;
if( pExpr->op==TK_COLUMN && pTab && !IsVirtual(pTab)
&& (pTab->aCol[pExpr->iColumn].colFlags & COLFLAG_SORTERREF)
-#if 0
- && pTab->pSchema && pTab->pSelect==0 && !IsVirtual(pTab)
-#endif
){
int j;
for(j=0; j<nDefer; j++){
int iParm = pDest->iSDParm; /* First argument to disposal method */
int nResultCol; /* Number of result columns */
int nPrefixReg = 0; /* Number of extra registers before regResult */
+ RowLoadInfo sRowLoadInfo; /* Info for deferred row loading */
/* Usually, regResult is the first cell in an array of memory cells
** containing the current result row. In this case regOrig is set to the
/* If the destination is an EXISTS(...) expression, the actual
** values returned by the SELECT are not required.
*/
- u8 ecelFlags;
+ u8 ecelFlags; /* "ecel" is an abbreviation of "ExprCodeExprList" */
+ ExprList *pEList;
if( eDest==SRT_Mem || eDest==SRT_Output || eDest==SRT_Coroutine ){
ecelFlags = SQLITE_ECEL_DUP;
}else{
** This allows the p->pEList field to be omitted from the sorted record,
** saving space and CPU cycles. */
ecelFlags |= (SQLITE_ECEL_OMITREF|SQLITE_ECEL_REF);
+
for(i=pSort->nOBSat; i<pSort->pOrderBy->nExpr; i++){
int j;
if( (j = pSort->pOrderBy->a[i].u.x.iOrderByCol)>0 ){
pParse->nMem += pExtra->nExpr;
}
#endif
- regOrig = 0;
+
+ /* Adjust nResultCol to account for columns that are omitted
+ ** from the sorter by the optimizations in this branch */
+ pEList = p->pEList;
+ for(i=0; i<pEList->nExpr; i++){
+ if( pEList->a[i].u.x.iOrderByCol>0
+#ifdef SQLITE_ENABLE_SORTER_REFERENCES
+ || pEList->a[i].bSorterRef
+#endif
+ ){
+ nResultCol--;
+ regOrig = 0;
+ }
+ }
+
+ testcase( regOrig );
+ testcase( eDest==SRT_Set );
+ testcase( eDest==SRT_Mem );
+ testcase( eDest==SRT_Coroutine );
+ testcase( eDest==SRT_Output );
assert( eDest==SRT_Set || eDest==SRT_Mem
|| eDest==SRT_Coroutine || eDest==SRT_Output );
}
- nResultCol = sqlite3ExprCodeExprList(pParse,p->pEList,regResult,
- 0,ecelFlags);
+ sRowLoadInfo.regResult = regResult;
+ sRowLoadInfo.ecelFlags = ecelFlags;
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
- if( pExtra ){
- nResultCol += sqlite3ExprCodeExprList(
- pParse, pExtra, regResult + nResultCol, 0, 0
- );
- sqlite3ExprListDelete(pParse->db, pExtra);
- }
+ sRowLoadInfo.pExtra = pExtra;
+ sRowLoadInfo.regExtraResult = regResult + nResultCol;
+ if( pExtra ) nResultCol += pExtra->nExpr;
#endif
+ if( p->iLimit
+ && (ecelFlags & SQLITE_ECEL_OMITREF)!=0
+ && nPrefixReg>0
+ ){
+ assert( pSort!=0 );
+ assert( hasDistinct==0 );
+ pSort->pDeferredRowLoad = &sRowLoadInfo;
+ }else{
+ innerLoopLoadRow(pParse, p, &sRowLoadInfo);
+ }
}
/* If the DISTINCT keyword was present on the SELECT statement
}
#endif
if( pSort ){
- pushOntoSorter(pParse, pSort, p, r1+nPrefixReg,regResult,1,nPrefixReg);
+ assert( regResult==regOrig );
+ pushOntoSorter(pParse, pSort, p, r1+nPrefixReg, regOrig, 1, nPrefixReg);
}else{
int r2 = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2);