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Overview
Comment: | Completely remove the iScanRatio field. The PRAGMA index_list(TABLE) command shows the estimated row size in the forth column. It also generates a row for the table with an index name of NULL. The query planner still does not take row size estimates into account - that is the next step. |
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Timelines: | family | ancestors | descendants | both | row-size-est |
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SHA1: |
8b4aa0c7a2122bbe60432edadf27e490 |
User & Date: | drh 2013-10-05 19:18:00.706 |
Context
2013-10-05
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20:18 | Fix an issue in the test8.c test module that arises because of the change to PRAGMA index_list(). Remove an unused local variable. (check-in: 029430c503 user: drh tags: row-size-est) | |
19:18 | Completely remove the iScanRatio field. The PRAGMA index_list(TABLE) command shows the estimated row size in the forth column. It also generates a row for the table with an index name of NULL. The query planner still does not take row size estimates into account - that is the next step. (check-in: 8b4aa0c7a2 user: drh tags: row-size-est) | |
18:32 | Improvements to the LogEst command-line tool used to convert between ordinary numbers and the LogEst representation. (check-in: 5252aeb619 user: drh tags: row-size-est) | |
Changes
Changes to src/analyze.c.
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1273 1274 1275 1276 1277 1278 1279 | } aOut[i] = v; if( *z==' ' ) z++; } if( pIndex ){ if( strcmp(z, "unordered")==0 ){ pIndex->bUnordered = 1; | | | < < < < < < < | | 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 | } aOut[i] = v; if( *z==' ' ) z++; } if( pIndex ){ if( strcmp(z, "unordered")==0 ){ pIndex->bUnordered = 1; }else if( sqlite3_strglob("sz=[0-9]*", z)==0 ){ int v32 = 0; sqlite3GetInt32(z+3, &v32); pIndex->szIdxRow = sqlite3LogEst(v32); } } } /* ** This callback is invoked once for each index when reading the ** sqlite_stat1 table. |
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Changes to src/build.c.
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1504 1505 1506 1507 1508 1509 1510 | sqlite3_snprintf(n-k, &zStmt[k], "%s", zEnd); return zStmt; } /* ** Estimate the total row width for a table. */ | | | | < < | < | < < | 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 | sqlite3_snprintf(n-k, &zStmt[k], "%s", zEnd); return zStmt; } /* ** Estimate the total row width for a table. */ static void estimateTableWidth(Table *pTab){ unsigned wTable = 0; const Column *pTabCol; int i; for(i=pTab->nCol, pTabCol=pTab->aCol; i>0; i--, pTabCol++){ wTable += pTabCol->szEst; } if( pTab->iPKey<0 ) wTable++; pTab->szTabRow = sqlite3LogEst(wTable*4); } /* ** Estimate the average size of a row for an index. */ static void estimateIndexWidth(Index *pIdx){ unsigned wIndex = 1; int i; const Column *aCol = pIdx->pTable->aCol; for(i=0; i<pIdx->nColumn; i++){ assert( pIdx->aiColumn[i]>=0 && pIdx->aiColumn[i]<pIdx->pTable->nCol ); wIndex += aCol[pIdx->aiColumn[i]].szEst; } pIdx->szIdxRow = sqlite3LogEst(wIndex*4); } /* ** This routine is called to report the final ")" that terminates ** a CREATE TABLE statement. ** ** The table structure that other action routines have been building |
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1584 1585 1586 1587 1588 1589 1590 | /* Resolve names in all CHECK constraint expressions. */ if( p->pCheck ){ sqlite3ResolveSelfReference(pParse, p, NC_IsCheck, 0, p->pCheck); } #endif /* !defined(SQLITE_OMIT_CHECK) */ | | | | | 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 | /* Resolve names in all CHECK constraint expressions. */ if( p->pCheck ){ sqlite3ResolveSelfReference(pParse, p, NC_IsCheck, 0, p->pCheck); } #endif /* !defined(SQLITE_OMIT_CHECK) */ /* Estimate the average row size for the table and for all implied indices */ estimateTableWidth(p); for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){ estimateIndexWidth(pIdx); } /* If the db->init.busy is 1 it means we are reading the SQL off the ** "sqlite_master" or "sqlite_temp_master" table on the disk. ** So do not write to the disk again. Extract the root page number ** for the table from the db->init.newTnum field. (The page number ** should have been put there by the sqliteOpenCb routine.) |
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2814 2815 2816 2817 2818 2819 2820 | } pIndex->azColl[i] = zColl; requestedSortOrder = pListItem->sortOrder & sortOrderMask; pIndex->aSortOrder[i] = (u8)requestedSortOrder; if( pTab->aCol[j].notNull==0 ) pIndex->uniqNotNull = 0; } sqlite3DefaultRowEst(pIndex); | | < < | 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 | } pIndex->azColl[i] = zColl; requestedSortOrder = pListItem->sortOrder & sortOrderMask; pIndex->aSortOrder[i] = (u8)requestedSortOrder; if( pTab->aCol[j].notNull==0 ) pIndex->uniqNotNull = 0; } sqlite3DefaultRowEst(pIndex); if( pParse->pNewTable==0 ) estimateIndexWidth(pIndex); if( pTab==pParse->pNewTable ){ /* This routine has been called to create an automatic index as a ** result of a PRIMARY KEY or UNIQUE clause on a column definition, or ** a PRIMARY KEY or UNIQUE clause following the column definitions. ** i.e. one of: ** |
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Changes to src/pragma.c.
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1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 | } } break; case PragTyp_INDEX_LIST: if( zRight ){ Index *pIdx; Table *pTab; pTab = sqlite3FindTable(db, zRight, zDb); if( pTab ){ v = sqlite3GetVdbe(pParse); | > < < < | | | | | | | > > > > > > | | | | | > | < < < | 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 | } } break; case PragTyp_INDEX_LIST: if( zRight ){ Index *pIdx; Table *pTab; int i; pTab = sqlite3FindTable(db, zRight, zDb); if( pTab ){ v = sqlite3GetVdbe(pParse); sqlite3VdbeSetNumCols(v, 4); pParse->nMem = 4; sqlite3CodeVerifySchema(pParse, iDb); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC); sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC); sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", SQLITE_STATIC); sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "avgrowsize", SQLITE_STATIC); sqlite3VdbeAddOp2(v, OP_Integer, 0, 1); sqlite3VdbeAddOp2(v, OP_Null, 0, 2); sqlite3VdbeAddOp2(v, OP_Integer, 1, 3); sqlite3VdbeAddOp2(v, OP_Integer, (int)sqlite3LogEstToInt(pTab->szTabRow), 4); sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 4); for(pIdx=pTab->pIndex, i=1; pIdx; pIdx=pIdx->pNext, i++){ sqlite3VdbeAddOp2(v, OP_Integer, i, 1); sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pIdx->zName, 0); sqlite3VdbeAddOp2(v, OP_Integer, pIdx->onError!=OE_None, 3); sqlite3VdbeAddOp2(v, OP_Integer, (int)sqlite3LogEstToInt(pIdx->szIdxRow), 4); sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 4); } } } break; case PragTyp_DATABASE_LIST: { int i; |
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Changes to src/select.c.
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4604 4605 4606 4607 4608 4609 4610 | ** (2013-10-03) Do not count the entires in a partial index. ** ** In practice the KeyInfo structure will not be used. It is only ** passed to keep OP_OpenRead happy. */ for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ if( pIdx->bUnordered==0 | | | | 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 | ** (2013-10-03) Do not count the entires in a partial index. ** ** In practice the KeyInfo structure will not be used. It is only ** passed to keep OP_OpenRead happy. */ for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ if( pIdx->bUnordered==0 && pIdx->szIdxRow<pTab->szTabRow && pIdx->pPartIdxWhere==0 && (!pBest || pIdx->szIdxRow<pBest->szIdxRow) ){ pBest = pIdx; } } if( pBest ){ iRoot = pBest->tnum; pKeyInfo = sqlite3IndexKeyinfo(pParse, pBest); |
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Changes to src/sqliteInt.h.
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1584 1585 1586 1587 1588 1589 1590 | Schema *pSchema; /* Schema containing this index */ u8 *aSortOrder; /* for each column: True==DESC, False==ASC */ char **azColl; /* Array of collation sequence names for index */ Expr *pPartIdxWhere; /* WHERE clause for partial indices */ int tnum; /* DB Page containing root of this index */ LogEst szIdxRow; /* Estimated average row size in bytes */ u16 nColumn; /* Number of columns in table used by this index */ | < | 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 | Schema *pSchema; /* Schema containing this index */ u8 *aSortOrder; /* for each column: True==DESC, False==ASC */ char **azColl; /* Array of collation sequence names for index */ Expr *pPartIdxWhere; /* WHERE clause for partial indices */ int tnum; /* DB Page containing root of this index */ LogEst szIdxRow; /* Estimated average row size in bytes */ u16 nColumn; /* Number of columns in table used by this index */ u8 onError; /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */ unsigned autoIndex:2; /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */ unsigned bUnordered:1; /* Use this index for == or IN queries only */ unsigned uniqNotNull:1; /* True if UNIQUE and NOT NULL for all columns */ #ifdef SQLITE_ENABLE_STAT3_OR_STAT4 int nSample; /* Number of elements in aSample[] */ int nSampleCol; /* Size of IndexSample.anEq[] and so on */ |
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Changes to src/where.c.
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4565 4566 4567 4568 4569 4570 4571 | /* Integer primary key index */ pNew->wsFlags = WHERE_IPK; /* Full table scan */ pNew->iSortIdx = b ? iSortIdx : 0; /* TUNING: Cost of full table scan is 3*(N + log2(N)). ** + The extra 3 factor is to encourage the use of indexed lookups | | < | | | 4565 4566 4567 4568 4569 4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605 | /* Integer primary key index */ pNew->wsFlags = WHERE_IPK; /* Full table scan */ pNew->iSortIdx = b ? iSortIdx : 0; /* TUNING: Cost of full table scan is 3*(N + log2(N)). ** + The extra 3 factor is to encourage the use of indexed lookups ** over full scans. FIXME */ pNew->rRun = sqlite3LogEstAdd(rSize,rLogSize) + 16; whereLoopOutputAdjust(pWC, pNew, pSrc->iCursor); rc = whereLoopInsert(pBuilder, pNew); pNew->nOut = rSize; if( rc ) break; }else{ Bitmask m = pSrc->colUsed & ~columnsInIndex(pProbe); pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED; /* Full scan via index */ if( b || ( m==0 && pProbe->bUnordered==0 && (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 && sqlite3GlobalConfig.bUseCis && OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan) ) ){ pNew->iSortIdx = b ? iSortIdx : 0; if( m==0 ){ /* TUNING: Cost of a covering index scan is K*(N + log2(N)). ** + The extra factor K of between 1.1 (iScanRatio between 0 ** and 9) and 2.8 (iScanRatio between 126 and 127) is added ** to encourage the use of indexed lookups. FIXME */ pNew->rRun = sqlite3LogEstAdd(rSize,rLogSize) + 10; }else{ assert( b!=0 ); /* TUNING: Cost of scanning a non-covering index is (N+1)*log2(N) ** which we will simplify to just N*log2(N) */ pNew->rRun = rSize + rLogSize; } whereLoopOutputAdjust(pWC, pNew, pSrc->iCursor); |
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