diff options
Diffstat (limited to 'src/backend/executor/execTuples.c')
| -rw-r--r-- | src/backend/executor/execTuples.c | 114 |
1 files changed, 85 insertions, 29 deletions
diff --git a/src/backend/executor/execTuples.c b/src/backend/executor/execTuples.c index 5df89e419c8..c46d65cf938 100644 --- a/src/backend/executor/execTuples.c +++ b/src/backend/executor/execTuples.c @@ -58,7 +58,7 @@ * At ExecutorStart() * ---------------- * - ExecInitSeqScan() calls ExecInitScanTupleSlot() and - * ExecInitResultTupleSlot() to construct TupleTableSlots + * ExecInitResultTupleSlotTL() to construct TupleTableSlots * for the tuples returned by the access methods and the * tuples resulting from performing target list projections. * @@ -104,19 +104,36 @@ static TupleDesc ExecTypeFromTLInternal(List *targetList, /* -------------------------------- * MakeTupleTableSlot * - * Basic routine to make an empty TupleTableSlot. + * Basic routine to make an empty TupleTableSlot. If tupleDesc is + * specified the slot's descriptor is fixed for it's lifetime, gaining + * some efficiency. If that's undesirable, pass NULL. * -------------------------------- */ TupleTableSlot * -MakeTupleTableSlot(void) +MakeTupleTableSlot(TupleDesc tupleDesc) { - TupleTableSlot *slot = makeNode(TupleTableSlot); + Size sz; + TupleTableSlot *slot; + /* + * When a fixed descriptor is specified, we can reduce overhead by + * allocating the entire slot in one go. + */ + if (tupleDesc) + sz = MAXALIGN(sizeof(TupleTableSlot)) + + MAXALIGN(tupleDesc->natts * sizeof(Datum)) + + MAXALIGN(tupleDesc->natts * sizeof(bool)); + else + sz = sizeof(TupleTableSlot); + + slot = palloc0(sz); + slot->type = T_TupleTableSlot; slot->tts_isempty = true; slot->tts_shouldFree = false; slot->tts_shouldFreeMin = false; slot->tts_tuple = NULL; - slot->tts_tupleDescriptor = NULL; + slot->tts_fixedTupleDescriptor = tupleDesc != NULL; + slot->tts_tupleDescriptor = tupleDesc; slot->tts_mcxt = CurrentMemoryContext; slot->tts_buffer = InvalidBuffer; slot->tts_nvalid = 0; @@ -124,6 +141,19 @@ MakeTupleTableSlot(void) slot->tts_isnull = NULL; slot->tts_mintuple = NULL; + if (tupleDesc != NULL) + { + slot->tts_values = (Datum *) + (((char *) slot) + + MAXALIGN(sizeof(TupleTableSlot))); + slot->tts_isnull = (bool *) + (((char *) slot) + + MAXALIGN(sizeof(TupleTableSlot)) + + MAXALIGN(tupleDesc->natts * sizeof(Datum))); + + PinTupleDesc(tupleDesc); + } + return slot; } @@ -134,9 +164,9 @@ MakeTupleTableSlot(void) * -------------------------------- */ TupleTableSlot * -ExecAllocTableSlot(List **tupleTable) +ExecAllocTableSlot(List **tupleTable, TupleDesc desc) { - TupleTableSlot *slot = MakeTupleTableSlot(); + TupleTableSlot *slot = MakeTupleTableSlot(desc); *tupleTable = lappend(*tupleTable, slot); @@ -173,10 +203,13 @@ ExecResetTupleTable(List *tupleTable, /* tuple table */ /* If shouldFree, release memory occupied by the slot itself */ if (shouldFree) { - if (slot->tts_values) - pfree(slot->tts_values); - if (slot->tts_isnull) - pfree(slot->tts_isnull); + if (!slot->tts_fixedTupleDescriptor) + { + if (slot->tts_values) + pfree(slot->tts_values); + if (slot->tts_isnull) + pfree(slot->tts_isnull); + } pfree(slot); } } @@ -198,9 +231,7 @@ ExecResetTupleTable(List *tupleTable, /* tuple table */ TupleTableSlot * MakeSingleTupleTableSlot(TupleDesc tupdesc) { - TupleTableSlot *slot = MakeTupleTableSlot(); - - ExecSetSlotDescriptor(slot, tupdesc); + TupleTableSlot *slot = MakeTupleTableSlot(tupdesc); return slot; } @@ -220,10 +251,13 @@ ExecDropSingleTupleTableSlot(TupleTableSlot *slot) ExecClearTuple(slot); if (slot->tts_tupleDescriptor) ReleaseTupleDesc(slot->tts_tupleDescriptor); - if (slot->tts_values) - pfree(slot->tts_values); - if (slot->tts_isnull) - pfree(slot->tts_isnull); + if (!slot->tts_fixedTupleDescriptor) + { + if (slot->tts_values) + pfree(slot->tts_values); + if (slot->tts_isnull) + pfree(slot->tts_isnull); + } pfree(slot); } @@ -247,6 +281,8 @@ void ExecSetSlotDescriptor(TupleTableSlot *slot, /* slot to change */ TupleDesc tupdesc) /* new tuple descriptor */ { + Assert(!slot->tts_fixedTupleDescriptor); + /* For safety, make sure slot is empty before changing it */ ExecClearTuple(slot); @@ -816,7 +852,7 @@ ExecCopySlot(TupleTableSlot *dstslot, TupleTableSlot *srcslot) */ /* -------------------------------- - * ExecInit{Result,Scan,Extra}TupleSlot + * ExecInit{Result,Scan,Extra}TupleSlot[TL] * * These are convenience routines to initialize the specified slot * in nodes inheriting the appropriate state. ExecInitExtraTupleSlot @@ -825,13 +861,30 @@ ExecCopySlot(TupleTableSlot *dstslot, TupleTableSlot *srcslot) */ /* ---------------- - * ExecInitResultTupleSlot + * ExecInitResultTupleSlotTL + * + * Initialize result tuple slot, using the plan node's targetlist. * ---------------- */ void -ExecInitResultTupleSlot(EState *estate, PlanState *planstate) +ExecInitResultTupleSlotTL(EState *estate, PlanState *planstate) { - planstate->ps_ResultTupleSlot = ExecAllocTableSlot(&estate->es_tupleTable); + bool hasoid; + TupleDesc tupDesc; + + if (ExecContextForcesOids(planstate, &hasoid)) + { + /* context forces OID choice; hasoid is now set correctly */ + } + else + { + /* given free choice, don't leave space for OIDs in result tuples */ + hasoid = false; + } + + tupDesc = ExecTypeFromTL(planstate->plan->targetlist, hasoid); + + planstate->ps_ResultTupleSlot = ExecAllocTableSlot(&estate->es_tupleTable, tupDesc); } /* ---------------- @@ -839,19 +892,24 @@ ExecInitResultTupleSlot(EState *estate, PlanState *planstate) * ---------------- */ void -ExecInitScanTupleSlot(EState *estate, ScanState *scanstate) +ExecInitScanTupleSlot(EState *estate, ScanState *scanstate, TupleDesc tupledesc) { - scanstate->ss_ScanTupleSlot = ExecAllocTableSlot(&estate->es_tupleTable); + scanstate->ss_ScanTupleSlot = ExecAllocTableSlot(&estate->es_tupleTable, + tupledesc); } /* ---------------- * ExecInitExtraTupleSlot + * + * Return a newly created slot. If tupledesc is non-NULL the slot will have + * that as its fixed tupledesc. Otherwise the caller needs to use + * ExecSetSlotDescriptor() to set the descriptor before use. * ---------------- */ TupleTableSlot * -ExecInitExtraTupleSlot(EState *estate) +ExecInitExtraTupleSlot(EState *estate, TupleDesc tupledesc) { - return ExecAllocTableSlot(&estate->es_tupleTable); + return ExecAllocTableSlot(&estate->es_tupleTable, tupledesc); } /* ---------------- @@ -865,9 +923,7 @@ ExecInitExtraTupleSlot(EState *estate) TupleTableSlot * ExecInitNullTupleSlot(EState *estate, TupleDesc tupType) { - TupleTableSlot *slot = ExecInitExtraTupleSlot(estate); - - ExecSetSlotDescriptor(slot, tupType); + TupleTableSlot *slot = ExecInitExtraTupleSlot(estate, tupType); return ExecStoreAllNullTuple(slot); } |