diff options
Diffstat (limited to 'src/backend/executor/execQual.c')
| -rw-r--r-- | src/backend/executor/execQual.c | 150 |
1 files changed, 83 insertions, 67 deletions
diff --git a/src/backend/executor/execQual.c b/src/backend/executor/execQual.c index d66bf4da822..21a9eb1753c 100644 --- a/src/backend/executor/execQual.c +++ b/src/backend/executor/execQual.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.243 2009/03/27 18:30:21 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.244 2009/04/02 22:39:29 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -4966,6 +4966,7 @@ ExecCleanTargetListLength(List *targetlist) * prepared to deal with sets of result tuples. Otherwise, a return * of *isDone = ExprMultipleResult signifies a set element, and a return * of *isDone = ExprEndResult signifies end of the set of tuple. + * We assume that *isDone has been initialized to ExprSingleResult by caller. */ static bool ExecTargetList(List *targetlist, @@ -4987,9 +4988,6 @@ ExecTargetList(List *targetlist, /* * evaluate all the expressions in the target list */ - if (isDone) - *isDone = ExprSingleResult; /* until proven otherwise */ - haveDoneSets = false; /* any exhausted set exprs in tlist? */ foreach(tl, targetlist) @@ -5105,50 +5103,6 @@ ExecTargetList(List *targetlist, } /* - * ExecVariableList - * Evaluates a simple-Variable-list projection. - * - * Results are stored into the passed values and isnull arrays. - */ -static void -ExecVariableList(ProjectionInfo *projInfo, - Datum *values, - bool *isnull) -{ - ExprContext *econtext = projInfo->pi_exprContext; - int *varSlotOffsets = projInfo->pi_varSlotOffsets; - int *varNumbers = projInfo->pi_varNumbers; - int i; - - /* - * Force extraction of all input values that we need. - */ - if (projInfo->pi_lastInnerVar > 0) - slot_getsomeattrs(econtext->ecxt_innertuple, - projInfo->pi_lastInnerVar); - if (projInfo->pi_lastOuterVar > 0) - slot_getsomeattrs(econtext->ecxt_outertuple, - projInfo->pi_lastOuterVar); - if (projInfo->pi_lastScanVar > 0) - slot_getsomeattrs(econtext->ecxt_scantuple, - projInfo->pi_lastScanVar); - - /* - * Assign to result by direct extraction of fields from source slots ... a - * mite ugly, but fast ... - */ - for (i = list_length(projInfo->pi_targetlist) - 1; i >= 0; i--) - { - char *slotptr = ((char *) econtext) + varSlotOffsets[i]; - TupleTableSlot *varSlot = *((TupleTableSlot **) slotptr); - int varNumber = varNumbers[i] - 1; - - values[i] = varSlot->tts_values[varNumber]; - isnull[i] = varSlot->tts_isnull[varNumber]; - } -} - -/* * ExecProject * * projects a tuple based on projection info and stores @@ -5165,6 +5119,8 @@ TupleTableSlot * ExecProject(ProjectionInfo *projInfo, ExprDoneCond *isDone) { TupleTableSlot *slot; + ExprContext *econtext; + int numSimpleVars; /* * sanity checks @@ -5175,6 +5131,11 @@ ExecProject(ProjectionInfo *projInfo, ExprDoneCond *isDone) * get the projection info we want */ slot = projInfo->pi_slot; + econtext = projInfo->pi_exprContext; + + /* Assume single result row until proven otherwise */ + if (isDone) + *isDone = ExprSingleResult; /* * Clear any former contents of the result slot. This makes it safe for @@ -5184,29 +5145,84 @@ ExecProject(ProjectionInfo *projInfo, ExprDoneCond *isDone) ExecClearTuple(slot); /* - * form a new result tuple (if possible); if successful, mark the result - * slot as containing a valid virtual tuple + * Force extraction of all input values that we'll need. The + * Var-extraction loops below depend on this, and we are also prefetching + * all attributes that will be referenced in the generic expressions. + */ + if (projInfo->pi_lastInnerVar > 0) + slot_getsomeattrs(econtext->ecxt_innertuple, + projInfo->pi_lastInnerVar); + if (projInfo->pi_lastOuterVar > 0) + slot_getsomeattrs(econtext->ecxt_outertuple, + projInfo->pi_lastOuterVar); + if (projInfo->pi_lastScanVar > 0) + slot_getsomeattrs(econtext->ecxt_scantuple, + projInfo->pi_lastScanVar); + + /* + * Assign simple Vars to result by direct extraction of fields from source + * slots ... a mite ugly, but fast ... */ - if (projInfo->pi_isVarList) + numSimpleVars = projInfo->pi_numSimpleVars; + if (numSimpleVars > 0) { - /* simple Var list: this always succeeds with one result row */ - if (isDone) - *isDone = ExprSingleResult; - ExecVariableList(projInfo, - slot->tts_values, - slot->tts_isnull); - ExecStoreVirtualTuple(slot); + Datum *values = slot->tts_values; + bool *isnull = slot->tts_isnull; + int *varSlotOffsets = projInfo->pi_varSlotOffsets; + int *varNumbers = projInfo->pi_varNumbers; + int i; + + if (projInfo->pi_directMap) + { + /* especially simple case where vars go to output in order */ + for (i = 0; i < numSimpleVars; i++) + { + char *slotptr = ((char *) econtext) + varSlotOffsets[i]; + TupleTableSlot *varSlot = *((TupleTableSlot **) slotptr); + int varNumber = varNumbers[i] - 1; + + values[i] = varSlot->tts_values[varNumber]; + isnull[i] = varSlot->tts_isnull[varNumber]; + } + } + else + { + /* we have to pay attention to varOutputCols[] */ + int *varOutputCols = projInfo->pi_varOutputCols; + + for (i = 0; i < numSimpleVars; i++) + { + char *slotptr = ((char *) econtext) + varSlotOffsets[i]; + TupleTableSlot *varSlot = *((TupleTableSlot **) slotptr); + int varNumber = varNumbers[i] - 1; + int varOutputCol = varOutputCols[i] - 1; + + values[varOutputCol] = varSlot->tts_values[varNumber]; + isnull[varOutputCol] = varSlot->tts_isnull[varNumber]; + } + } } - else + + /* + * If there are any generic expressions, evaluate them. It's possible + * that there are set-returning functions in such expressions; if so + * and we have reached the end of the set, we return the result slot, + * which we already marked empty. + */ + if (projInfo->pi_targetlist) { - if (ExecTargetList(projInfo->pi_targetlist, - projInfo->pi_exprContext, - slot->tts_values, - slot->tts_isnull, - projInfo->pi_itemIsDone, - isDone)) - ExecStoreVirtualTuple(slot); + if (!ExecTargetList(projInfo->pi_targetlist, + econtext, + slot->tts_values, + slot->tts_isnull, + projInfo->pi_itemIsDone, + isDone)) + return slot; /* no more result rows, return empty slot */ } - return slot; + /* + * Successfully formed a result row. Mark the result slot as containing a + * valid virtual tuple. + */ + return ExecStoreVirtualTuple(slot); } |