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Overview
Comment: | Faster allocation of new sqlite3_stmt objects. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA3-256: |
891f1f72187f0f9ec0d24fda98cc08be |
User & Date: | drh 2018-12-28 20:48:07.501 |
Context
2018-12-29
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02:26 | A new implementation of sqlite3VdbeMakeLabel() is faster and makes fewer memory allocations by deferring memory allocation until sqlite3VdbeResolveLabel() is called, at which point the code generator has a better idea of how big the relocation table needs to be. The sqlite3VdbeMakeLabel() routine now takes a Parse* parameter instead of Vdbe*. (check-in: 4a0929ac76 user: drh tags: trunk) | |
2018-12-28
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21:32 | Merge performance enhancements from trunk. (check-in: 0f1b9ff9e1 user: drh tags: reuse-subqueries) | |
20:48 | Faster allocation of new sqlite3_stmt objects. (check-in: 891f1f7218 user: drh tags: trunk) | |
20:14 | Move the nOpAlloc field from Parse into Vdbe to avoid an extra pointer deference on the fast path in sqlite3VdbeAddOp3(). (check-in: 8f10efc29d user: drh tags: trunk) | |
Changes
Changes to src/vdbeInt.h.
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381 382 383 384 385 386 387 388 389 390 391 392 393 394 | int rc; /* Value to return */ int nChange; /* Number of db changes made since last reset */ int iStatement; /* Statement number (or 0 if has no opened stmt) */ i64 iCurrentTime; /* Value of julianday('now') for this statement */ i64 nFkConstraint; /* Number of imm. FK constraints this VM */ i64 nStmtDefCons; /* Number of def. constraints when stmt started */ i64 nStmtDefImmCons; /* Number of def. imm constraints when stmt started */ /* When allocating a new Vdbe object, all of the fields below should be ** initialized to zero or NULL */ Op *aOp; /* Space to hold the virtual machine's program */ int nOp; /* Number of instructions in the program */ int nOpAlloc; /* Slots allocated for aOp[] */ | > > > > < < < < | 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 | int rc; /* Value to return */ int nChange; /* Number of db changes made since last reset */ int iStatement; /* Statement number (or 0 if has no opened stmt) */ i64 iCurrentTime; /* Value of julianday('now') for this statement */ i64 nFkConstraint; /* Number of imm. FK constraints this VM */ i64 nStmtDefCons; /* Number of def. constraints when stmt started */ i64 nStmtDefImmCons; /* Number of def. imm constraints when stmt started */ Mem *aMem; /* The memory locations */ Mem **apArg; /* Arguments to currently executing user function */ VdbeCursor **apCsr; /* One element of this array for each open cursor */ Mem *aVar; /* Values for the OP_Variable opcode. */ /* When allocating a new Vdbe object, all of the fields below should be ** initialized to zero or NULL */ Op *aOp; /* Space to hold the virtual machine's program */ int nOp; /* Number of instructions in the program */ int nOpAlloc; /* Slots allocated for aOp[] */ Mem *aColName; /* Column names to return */ Mem *pResultSet; /* Pointer to an array of results */ char *zErrMsg; /* Error message written here */ VList *pVList; /* Name of variables */ #ifndef SQLITE_OMIT_TRACE i64 startTime; /* Time when query started - used for profiling */ #endif #ifdef SQLITE_DEBUG int rcApp; /* errcode set by sqlite3_result_error_code() */ u32 nWrite; /* Number of write operations that have occurred */ |
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Changes to src/vdbeaux.c.
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2183 2184 2185 2186 2187 2188 2189 | ** requirements by reusing the opcode array tail, then the second ** pass will fill in the remainder using a fresh memory allocation. ** ** This two-pass approach that reuses as much memory as possible from ** the leftover memory at the end of the opcode array. This can significantly ** reduce the amount of memory held by a prepared statement. */ | < | | | | | | | | > > > > > > > > > | 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 | ** requirements by reusing the opcode array tail, then the second ** pass will fill in the remainder using a fresh memory allocation. ** ** This two-pass approach that reuses as much memory as possible from ** the leftover memory at the end of the opcode array. This can significantly ** reduce the amount of memory held by a prepared statement. */ x.nNeeded = 0; p->aMem = allocSpace(&x, 0, nMem*sizeof(Mem)); p->aVar = allocSpace(&x, 0, nVar*sizeof(Mem)); p->apArg = allocSpace(&x, 0, nArg*sizeof(Mem*)); p->apCsr = allocSpace(&x, 0, nCursor*sizeof(VdbeCursor*)); #ifdef SQLITE_ENABLE_STMT_SCANSTATUS p->anExec = allocSpace(&x, 0, p->nOp*sizeof(i64)); #endif if( x.nNeeded ){ x.pSpace = p->pFree = sqlite3DbMallocRawNN(db, x.nNeeded); x.nFree = x.nNeeded; if( !db->mallocFailed ){ p->aMem = allocSpace(&x, p->aMem, nMem*sizeof(Mem)); p->aVar = allocSpace(&x, p->aVar, nVar*sizeof(Mem)); p->apArg = allocSpace(&x, p->apArg, nArg*sizeof(Mem*)); p->apCsr = allocSpace(&x, p->apCsr, nCursor*sizeof(VdbeCursor*)); #ifdef SQLITE_ENABLE_STMT_SCANSTATUS p->anExec = allocSpace(&x, p->anExec, p->nOp*sizeof(i64)); #endif } } p->pVList = pParse->pVList; pParse->pVList = 0; p->explain = pParse->explain; if( db->mallocFailed ){ p->nVar = 0; p->nCursor = 0; |
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