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Overview
Comment: | Small size and performance improvement in the OP_Column opcode. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA3-256: |
2cf3f3de8a48465bd6b0af7763bfe905 |
User & Date: | drh 2017-08-15 14:14:36.511 |
Original Comment: | Small size and performance in the OP_Column opcode. |
Context
2017-08-16
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11:04 | Performance improvement in the OP_Column opcode. (check-in: dc98a92f32 user: drh tags: trunk) | |
2017-08-15
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14:14 | Small size and performance improvement in the OP_Column opcode. (check-in: 2cf3f3de8a user: drh tags: trunk) | |
03:46 | Btree optimization: New field BtCursor.pPage that points to the current page, saving a single pointer dereference on each access. (check-in: 373b71d19c user: drh tags: trunk) | |
Changes
Changes to src/vdbe.c.
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2384 2385 2386 2387 2388 2389 2390 | Mem *pDest; /* Where to write the extracted value */ Mem sMem; /* For storing the record being decoded */ const u8 *zData; /* Part of the record being decoded */ const u8 *zHdr; /* Next unparsed byte of the header */ const u8 *zEndHdr; /* Pointer to first byte after the header */ u32 offset; /* Offset into the data */ u64 offset64; /* 64-bit offset */ | < | 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 | Mem *pDest; /* Where to write the extracted value */ Mem sMem; /* For storing the record being decoded */ const u8 *zData; /* Part of the record being decoded */ const u8 *zHdr; /* Next unparsed byte of the header */ const u8 *zEndHdr; /* Pointer to first byte after the header */ u32 offset; /* Offset into the data */ u64 offset64; /* 64-bit offset */ u32 t; /* A type code from the record header */ Mem *pReg; /* PseudoTable input register */ pC = p->apCsr[pOp->p1]; p2 = pOp->p2; /* If the cursor cache is stale (meaning it is not currently point at |
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2415 2416 2417 2418 2419 2420 2421 | if( pC->cacheStatus!=p->cacheCtr ){ /*OPTIMIZATION-IF-FALSE*/ if( pC->nullRow ){ if( pC->eCurType==CURTYPE_PSEUDO ){ assert( pC->uc.pseudoTableReg>0 ); pReg = &aMem[pC->uc.pseudoTableReg]; assert( pReg->flags & MEM_Blob ); assert( memIsValid(pReg) ); | | | > | < < | < < | | 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 | if( pC->cacheStatus!=p->cacheCtr ){ /*OPTIMIZATION-IF-FALSE*/ if( pC->nullRow ){ if( pC->eCurType==CURTYPE_PSEUDO ){ assert( pC->uc.pseudoTableReg>0 ); pReg = &aMem[pC->uc.pseudoTableReg]; assert( pReg->flags & MEM_Blob ); assert( memIsValid(pReg) ); pC->payloadSize = pC->szRow = pReg->n; pC->aRow = (u8*)pReg->z; }else{ sqlite3VdbeMemSetNull(pDest); goto op_column_out; } }else{ pCrsr = pC->uc.pCursor; assert( pC->eCurType==CURTYPE_BTREE ); assert( pCrsr ); assert( sqlite3BtreeCursorIsValid(pCrsr) ); pC->payloadSize = sqlite3BtreePayloadSize(pCrsr); pC->aRow = sqlite3BtreePayloadFetch(pCrsr, &pC->szRow); assert( pC->szRow<=pC->payloadSize ); assert( pC->szRow<=65536 ); /* Maximum page size is 64KiB */ if( pC->payloadSize > (u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){ goto too_big; } } pC->cacheStatus = p->cacheCtr; pC->iHdrOffset = getVarint32(pC->aRow, offset); pC->nHdrParsed = 0; aOffset[0] = offset; if( pC->szRow<offset ){ /*OPTIMIZATION-IF-FALSE*/ /* pC->aRow does not have to hold the entire row, but it does at least ** need to cover the header of the record. If pC->aRow does not contain ** the complete header, then set it to zero, forcing the header to be ** dynamically allocated. */ pC->aRow = 0; pC->szRow = 0; |
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