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Overview
| Comment: | Remove the sequence values from sorter records used by ORDER BY as well. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | orderby-planning |
| Files: | files | file ages | folders |
| SHA1: |
c3ae3697832a00d4d5758988a8766bdb |
| User & Date: | dan 2014-03-25 15:04:07 |
Context
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2014-03-25
| ||
| 17:07 | Fix a problem in the code added by [707ea170b3] causing vdbesort.c to sort unstably. (check-in: d3e640af user: dan tags: orderby-planning) | |
| 15:04 | Remove the sequence values from sorter records used by ORDER BY as well. (check-in: c3ae3697 user: dan tags: orderby-planning) | |
|
2014-03-24
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| 20:19 | Omit the sequence value from sorter records used by GROUP BY queries that cannot use an index. (check-in: 3f90abdd user: dan tags: orderby-planning) | |
Changes
Changes to src/select.c.
463 463 SortCtx *pSort, /* Information about the ORDER BY clause */ 464 464 Select *pSelect, /* The whole SELECT statement */ 465 465 int regData, /* First register holding data to be sorted */ 466 466 int nData, /* Number of elements in the data array */ 467 467 int nPrefixReg /* No. of reg prior to regData available for use */ 468 468 ){ 469 469 Vdbe *v = pParse->pVdbe; /* Stmt under construction */ 470 + int bSeq = ((pSort->sortFlags & SORTFLAG_UseSorter)==0); 470 471 int nExpr = pSort->pOrderBy->nExpr; /* No. of ORDER BY terms */ 471 - int nBase = nExpr + 1 + nData; /* Fields in sorter record */ 472 + int nBase = nExpr + bSeq + nData; /* Fields in sorter record */ 472 473 int regBase; /* Regs for sorter record */ 473 - int regRecord = sqlite3GetTempReg(pParse); /* Assemblied sorter record */ 474 - int nOBSat = pSort->nOBSat; /* No. ORDER BY terms to skip */ 475 - int op; /* Opcode to add sorter record to sorter */ 474 + int regRecord = sqlite3GetTempReg(pParse); /* Assembled sorter record */ 475 + int nOBSat = pSort->nOBSat; /* ORDER BY terms to skip */ 476 + int op; /* Opcode to add sorter record to sorter */ 476 477 478 + assert( bSeq==0 || bSeq==1 ); 477 479 if( nPrefixReg ){ 478 - assert( nPrefixReg==nExpr+1 ); 479 - regBase = regData - nExpr - 1; 480 + assert( nPrefixReg==nExpr+bSeq ); 481 + regBase = regData - nExpr - bSeq; 480 482 }else{ 481 483 regBase = sqlite3GetTempRange(pParse, nBase); 482 484 } 483 485 sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, SQLITE_ECEL_DUP); 484 - sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr); 486 + if( bSeq ){ 487 + sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr); 488 + } 485 489 if( nPrefixReg==0 ){ 486 - sqlite3VdbeAddOp3(v, OP_Move, regData, regBase+nExpr+1, nData); 490 + sqlite3VdbeAddOp3(v, OP_Move, regData, regBase+nExpr+bSeq, nData); 487 491 } 492 + 488 493 sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat, regRecord); 489 494 if( nOBSat>0 ){ 490 495 int regPrevKey; /* The first nOBSat columns of the previous row */ 491 496 int addrFirst; /* Address of the OP_IfNot opcode */ 492 497 int addrJmp; /* Address of the OP_Jump opcode */ 493 498 VdbeOp *pOp; /* Opcode that opens the sorter */ 494 499 int nKey; /* Number of sorting key columns, including OP_Sequence */ 495 500 KeyInfo *pKI; /* Original KeyInfo on the sorter table */ 496 501 497 502 regPrevKey = pParse->nMem+1; 498 503 pParse->nMem += pSort->nOBSat; 499 - nKey = nExpr - pSort->nOBSat + 1; 500 - addrFirst = sqlite3VdbeAddOp1(v, OP_IfNot, regBase+nExpr); VdbeCoverage(v); 504 + nKey = nExpr - pSort->nOBSat + bSeq; 505 + if( bSeq ){ 506 + addrFirst = sqlite3VdbeAddOp1(v, OP_IfNot, regBase+nExpr); 507 + }else{ 508 + addrFirst = sqlite3VdbeAddOp1(v, OP_SequenceTest, pSort->iECursor); 509 + } 510 + VdbeCoverage(v); 501 511 sqlite3VdbeAddOp3(v, OP_Compare, regPrevKey, regBase, pSort->nOBSat); 502 512 pOp = sqlite3VdbeGetOp(v, pSort->addrSortIndex); 503 513 if( pParse->db->mallocFailed ) return; 504 514 pOp->p2 = nKey + 1; 505 515 pKI = pOp->p4.pKeyInfo; 506 516 memset(pKI->aSortOrder, 0, pKI->nField); /* Makes OP_Jump below testable */ 507 517 sqlite3VdbeChangeP4(v, -1, (char*)pKI, P4_KEYINFO); ................................................................................ 655 665 656 666 /* Pull the requested columns. 657 667 */ 658 668 nResultCol = pEList->nExpr; 659 669 660 670 if( pDest->iSdst==0 ){ 661 671 if( pSort ){ 662 - nPrefixReg = pSort->pOrderBy->nExpr + 1; 672 + nPrefixReg = pSort->pOrderBy->nExpr; 673 + if( !(pSort->sortFlags & SORTFLAG_UseSorter) ) nPrefixReg++; 663 674 pParse->nMem += nPrefixReg; 664 675 } 665 676 pDest->iSdst = pParse->nMem+1; 666 677 pParse->nMem += nResultCol; 667 678 }else if( pDest->iSdst+nResultCol > pParse->nMem ){ 668 679 /* This is an error condition that can result, for example, when a SELECT 669 680 ** on the right-hand side of an INSERT contains more result columns than ................................................................................ 1148 1159 int regRow; 1149 1160 int regRowid; 1150 1161 int nKey; 1151 1162 int iSortTab; /* Sorter cursor to read from */ 1152 1163 int nSortData; /* Trailing values to read from sorter */ 1153 1164 u8 p5; /* p5 parameter for 1st OP_Column */ 1154 1165 int i; 1166 + int bSeq; /* True if sorter record includes seq. no. */ 1155 1167 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS 1156 1168 struct ExprList_item *aOutEx = p->pEList->a; 1157 1169 #endif 1158 1170 1159 1171 if( pSort->labelBkOut ){ 1160 1172 sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut); 1161 1173 sqlite3VdbeAddOp2(v, OP_Goto, 0, addrBreak); ................................................................................ 1181 1193 sqlite3VdbeAddOp3(v, OP_OpenPseudo, iSortTab, regSortOut, nKey+1+nSortData); 1182 1194 if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce); 1183 1195 addr = 1 + sqlite3VdbeAddOp2(v, OP_SorterSort, iTab, addrBreak); 1184 1196 VdbeCoverage(v); 1185 1197 codeOffset(v, p->iOffset, addrContinue); 1186 1198 sqlite3VdbeAddOp2(v, OP_SorterData, iTab, regSortOut); 1187 1199 p5 = OPFLAG_CLEARCACHE; 1200 + bSeq = 0; 1188 1201 }else{ 1189 1202 addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, addrBreak); VdbeCoverage(v); 1190 1203 codeOffset(v, p->iOffset, addrContinue); 1191 1204 iSortTab = iTab; 1192 1205 p5 = 0; 1206 + bSeq = 1; 1193 1207 } 1194 1208 for(i=0; i<nSortData; i++){ 1195 - sqlite3VdbeAddOp3(v, OP_Column, iSortTab, nKey+1+i, regRow+i); 1209 + sqlite3VdbeAddOp3(v, OP_Column, iSortTab, nKey+bSeq+i, regRow+i); 1196 1210 if( i==0 ) sqlite3VdbeChangeP5(v, p5); 1197 1211 VdbeComment((v, "%s", aOutEx[i].zName ? aOutEx[i].zName : aOutEx[i].zSpan)); 1198 1212 } 1199 1213 switch( eDest ){ 1200 1214 case SRT_Table: 1201 1215 case SRT_EphemTab: { 1202 1216 testcase( eDest==SRT_Table );
Changes to src/vdbe.c.
3380 3380 if( pCx==0 ) goto no_mem; 3381 3381 pCx->pKeyInfo = pOp->p4.pKeyInfo; 3382 3382 assert( pCx->pKeyInfo->db==db ); 3383 3383 assert( pCx->pKeyInfo->enc==ENC(db) ); 3384 3384 rc = sqlite3VdbeSorterInit(db, pCx); 3385 3385 break; 3386 3386 } 3387 + 3388 +/* Opcode: SequenceTest P1 P2 * * * 3389 +** Synopsis: if( cursor[P1].ctr++ ) pc = P2 3390 +** 3391 +** P1 is a sorter cursor. If the sequence counter is currently zero, jump 3392 +** to P2. Regardless of whether or not the jump is taken, increment the 3393 +** the sequence value. 3394 +*/ 3395 +case OP_SequenceTest: { 3396 + VdbeCursor *pC; 3397 + assert( pOp->p1>=0 && pOp->p1<p->nCursor ); 3398 + pC = p->apCsr[pOp->p1]; 3399 + assert( pC->pSorter ); 3400 + if( (pC->seqCount++)==0 ){ 3401 + pc = pOp->p2 - 1; 3402 + } 3403 + break; 3404 +} 3387 3405 3388 3406 /* Opcode: OpenPseudo P1 P2 P3 * * 3389 3407 ** Synopsis: P3 columns in r[P2] 3390 3408 ** 3391 3409 ** Open a new cursor that points to a fake table that contains a single 3392 3410 ** row of data. The content of that one row is the content of memory 3393 3411 ** register P2. In other words, cursor P1 becomes an alias for the