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Overview
Comment: | Initial implementation of an optimization that attempts to reuse the same materialization of a view on a self-join of the view. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | materialized-view-reuse |
Files: | files | file ages | folders |
SHA3-256: |
478c34b9a8b5127d13024e10307aa832 |
User & Date: | drh 2017-05-01 15:15:41.259 |
Context
2017-05-01
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16:37 | Minor bug fixes and performance enhancement. (check-in: b2aae55958 user: drh tags: materialized-view-reuse) | |
15:15 | Initial implementation of an optimization that attempts to reuse the same materialization of a view on a self-join of the view. (check-in: 478c34b9a8 user: drh tags: materialized-view-reuse) | |
2017-04-29
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19:29 | Add a single testcase() macro to the subquery processing logic. (check-in: 4e1df76e3d user: drh tags: trunk) | |
Changes
Changes to src/select.c.
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4874 4875 4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 | pParse->pVdbe, OP_Explain, pParse->iSelectId, 0, 0, zEqp, P4_DYNAMIC ); } } #else # define explainSimpleCount(a,b,c) #endif /* ** Generate code for the SELECT statement given in the p argument. ** ** The results are returned according to the SelectDest structure. ** See comments in sqliteInt.h for further information. ** | > > > > > > > > > > > > > > > > > > | 4874 4875 4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 | pParse->pVdbe, OP_Explain, pParse->iSelectId, 0, 0, zEqp, P4_DYNAMIC ); } } #else # define explainSimpleCount(a,b,c) #endif /* ** Check to see if the pThis entry of pTabList is a self-join of a prior view. ** If it is, then return the SrcList_item for the prior view. If it is not, ** then return 0. */ static struct SrcList_item *isSelfJoinView( SrcList *pTabList, /* Search for self-joins in this FROM clause */ struct SrcList_item *pThis /* Search for prior reference to this subquery */ ){ struct SrcList_item *pItem; for(pItem = pTabList->a; pItem<pThis; pItem++){ if( pItem->pSelect==0 ) continue; if( pItem->fg.viaCoroutine ) continue; if( sqlite3StrICmp(pItem->zName, pThis->zName)==0 ) return pItem; } return 0; } /* ** Generate code for the SELECT statement given in the p argument. ** ** The results are returned according to the SelectDest structure. ** See comments in sqliteInt.h for further information. ** |
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5109 5110 5111 5112 5113 5114 5115 5116 5117 5118 5119 5120 5121 5122 5123 5124 5125 5126 5127 5128 | ** the content of this subquery. pItem->addrFillSub will point ** to the address of the generated subroutine. pItem->regReturn ** is a register allocated to hold the subroutine return address */ int topAddr; int onceAddr = 0; int retAddr; assert( pItem->addrFillSub==0 ); pItem->regReturn = ++pParse->nMem; topAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pItem->regReturn); pItem->addrFillSub = topAddr+1; if( pItem->fg.isCorrelated==0 ){ /* If the subquery is not correlated and if we are not inside of ** a trigger, then we only need to compute the value of the subquery ** once. */ onceAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v); VdbeComment((v, "materialize \"%s\"", pItem->pTab->zName)); }else{ VdbeNoopComment((v, "materialize \"%s\"", pItem->pTab->zName)); } | > > > > > > | | | > | 5127 5128 5129 5130 5131 5132 5133 5134 5135 5136 5137 5138 5139 5140 5141 5142 5143 5144 5145 5146 5147 5148 5149 5150 5151 5152 5153 5154 5155 5156 5157 5158 5159 5160 5161 5162 5163 | ** the content of this subquery. pItem->addrFillSub will point ** to the address of the generated subroutine. pItem->regReturn ** is a register allocated to hold the subroutine return address */ int topAddr; int onceAddr = 0; int retAddr; struct SrcList_item *pPrior; assert( pItem->addrFillSub==0 ); pItem->regReturn = ++pParse->nMem; topAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pItem->regReturn); pItem->addrFillSub = topAddr+1; if( pItem->fg.isCorrelated==0 ){ /* If the subquery is not correlated and if we are not inside of ** a trigger, then we only need to compute the value of the subquery ** once. */ onceAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v); VdbeComment((v, "materialize \"%s\"", pItem->pTab->zName)); }else{ VdbeNoopComment((v, "materialize \"%s\"", pItem->pTab->zName)); } pPrior = isSelfJoinView(pTabList, pItem); if( pPrior ){ sqlite3VdbeAddOp2(v, OP_OpenDup, pItem->iCursor, pPrior->iCursor); }else{ sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor); explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId); sqlite3Select(pParse, pSub, &dest); } pItem->pTab->nRowLogEst = pSub->nSelectRow; if( onceAddr ) sqlite3VdbeJumpHere(v, onceAddr); retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn); VdbeComment((v, "end %s", pItem->pTab->zName)); sqlite3VdbeChangeP1(v, topAddr, retAddr); sqlite3ClearTempRegCache(pParse); } |
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Changes to src/vdbe.c.
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3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 | testcase( pOp->p2 & OPFLAG_SEEKEQ ); #endif sqlite3BtreeCursorHintFlags(pCur->uc.pCursor, (pOp->p5 & (OPFLAG_BULKCSR|OPFLAG_SEEKEQ))); if( rc ) goto abort_due_to_error; break; } /* Opcode: OpenEphemeral P1 P2 * P4 P5 ** Synopsis: nColumn=P2 ** ** Open a new cursor P1 to a transient table. ** The cursor is always opened read/write even if ** the main database is read-only. The ephemeral | > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 | testcase( pOp->p2 & OPFLAG_SEEKEQ ); #endif sqlite3BtreeCursorHintFlags(pCur->uc.pCursor, (pOp->p5 & (OPFLAG_BULKCSR|OPFLAG_SEEKEQ))); if( rc ) goto abort_due_to_error; break; } /* Opcode: OpenDup P1 P2 * * * ** ** Open a new cursor P1 that points to the same ephemeral table as ** cursor P2. The P2 cursor must have been opened by a prior OP_OpenEphemeral ** opcode. Only ephemeral cursors may be duplicated. ** ** Duplicate ephemeral cursors are used for self-joins of materialized views. */ case OP_OpenDup: { VdbeCursor *pOrig; /* The original cursor to be duplicated */ VdbeCursor *pCx; /* The new cursor */ pOrig = p->apCsr[pOp->p2]; assert( pOrig->pBtx!=0 ); /* Only ephemeral cursors can be duplicated */ pCx = allocateCursor(p, pOp->p1, pOrig->nField, -1, CURTYPE_BTREE); if( pCx==0 ) goto no_mem; pCx->nullRow = 1; pCx->isEphemeral = 1; pCx->pKeyInfo = pOrig->pKeyInfo; pCx->isTable = pOrig->isTable; rc = sqlite3BtreeCursor(pOrig->pBtx, MASTER_ROOT, BTREE_WRCSR, pCx->pKeyInfo, pCx->uc.pCursor); if( rc ) goto abort_due_to_error; break; } /* Opcode: OpenEphemeral P1 P2 * P4 P5 ** Synopsis: nColumn=P2 ** ** Open a new cursor P1 to a transient table. ** The cursor is always opened read/write even if ** the main database is read-only. The ephemeral |
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Changes to src/vdbeaux.c.
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2035 2036 2037 2038 2039 2040 2041 | break; } case CURTYPE_BTREE: { if( pCx->pBtx ){ sqlite3BtreeClose(pCx->pBtx); /* The pCx->pCursor will be close automatically, if it exists, by ** the call above. */ | | | 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 | break; } case CURTYPE_BTREE: { if( pCx->pBtx ){ sqlite3BtreeClose(pCx->pBtx); /* The pCx->pCursor will be close automatically, if it exists, by ** the call above. */ }else if( !pCx->isEphemeral ){ assert( pCx->uc.pCursor!=0 ); sqlite3BtreeCloseCursor(pCx->uc.pCursor); } break; } #ifndef SQLITE_OMIT_VIRTUALTABLE case CURTYPE_VTAB: { |
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