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-rw-r--r--src/backend/executor/execUtils.c198
1 files changed, 121 insertions, 77 deletions
diff --git a/src/backend/executor/execUtils.c b/src/backend/executor/execUtils.c
index 995e1477e3a..4b3d92d48b8 100644
--- a/src/backend/executor/execUtils.c
+++ b/src/backend/executor/execUtils.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/executor/execUtils.c,v 1.157 2009/01/01 17:23:41 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/executor/execUtils.c,v 1.158 2009/04/02 22:39:30 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -46,6 +46,7 @@
#include "access/heapam.h"
#include "catalog/index.h"
#include "executor/execdebug.h"
+#include "nodes/nodeFuncs.h"
#include "parser/parsetree.h"
#include "utils/memutils.h"
#include "utils/relcache.h"
@@ -66,6 +67,7 @@ int NIndexTupleInserted;
int NIndexTupleProcessed;
+static bool get_last_attnums(Node *node, ProjectionInfo *projInfo);
static void ShutdownExprContext(ExprContext *econtext);
@@ -559,121 +561,163 @@ ExecBuildProjectionInfo(List *targetList,
TupleDesc inputDesc)
{
ProjectionInfo *projInfo = makeNode(ProjectionInfo);
- int len;
- bool isVarList;
+ int len = ExecTargetListLength(targetList);
+ int *workspace;
+ int *varSlotOffsets;
+ int *varNumbers;
+ int *varOutputCols;
+ List *exprlist;
+ int numSimpleVars;
+ bool directMap;
ListCell *tl;
- len = ExecTargetListLength(targetList);
-
- projInfo->pi_targetlist = targetList;
projInfo->pi_exprContext = econtext;
projInfo->pi_slot = slot;
+ /* since these are all int arrays, we need do just one palloc */
+ workspace = (int *) palloc(len * 3 * sizeof(int));
+ projInfo->pi_varSlotOffsets = varSlotOffsets = workspace;
+ projInfo->pi_varNumbers = varNumbers = workspace + len;
+ projInfo->pi_varOutputCols = varOutputCols = workspace + len * 2;
+ projInfo->pi_lastInnerVar = 0;
+ projInfo->pi_lastOuterVar = 0;
+ projInfo->pi_lastScanVar = 0;
/*
- * Determine whether the target list consists entirely of simple Var
- * references (ie, references to non-system attributes) that match the
- * input. If so, we can use the simpler ExecVariableList instead of
- * ExecTargetList. (Note: if there is a type mismatch then ExecEvalVar
- * will probably throw an error at runtime, but we leave that to it.)
+ * We separate the target list elements into simple Var references and
+ * expressions which require the full ExecTargetList machinery. To be
+ * a simple Var, a Var has to be a user attribute and not mismatch the
+ * inputDesc. (Note: if there is a type mismatch then ExecEvalVar will
+ * probably throw an error at runtime, but we leave that to it.)
*/
- isVarList = true;
+ exprlist = NIL;
+ numSimpleVars = 0;
+ directMap = true;
foreach(tl, targetList)
{
GenericExprState *gstate = (GenericExprState *) lfirst(tl);
Var *variable = (Var *) gstate->arg->expr;
- Form_pg_attribute attr;
+ bool isSimpleVar = false;
- if (variable == NULL ||
- !IsA(variable, Var) ||
- variable->varattno <= 0)
- {
- isVarList = false;
- break;
- }
- if (!inputDesc)
- continue; /* can't check type, assume OK */
- if (variable->varattno > inputDesc->natts)
+ if (variable != NULL &&
+ IsA(variable, Var) &&
+ variable->varattno > 0)
{
- isVarList = false;
- break;
- }
- attr = inputDesc->attrs[variable->varattno - 1];
- if (attr->attisdropped || variable->vartype != attr->atttypid)
- {
- isVarList = false;
- break;
- }
- }
- projInfo->pi_isVarList = isVarList;
-
- if (isVarList)
- {
- int *varSlotOffsets;
- int *varNumbers;
- AttrNumber lastInnerVar = 0;
- AttrNumber lastOuterVar = 0;
- AttrNumber lastScanVar = 0;
+ if (!inputDesc)
+ isSimpleVar = true; /* can't check type, assume OK */
+ else if (variable->varattno <= inputDesc->natts)
+ {
+ Form_pg_attribute attr;
- projInfo->pi_itemIsDone = NULL; /* not needed */
- projInfo->pi_varSlotOffsets = varSlotOffsets = (int *)
- palloc0(len * sizeof(int));
- projInfo->pi_varNumbers = varNumbers = (int *)
- palloc0(len * sizeof(int));
+ attr = inputDesc->attrs[variable->varattno - 1];
+ if (!attr->attisdropped && variable->vartype == attr->atttypid)
+ isSimpleVar = true;
+ }
+ }
- /*
- * Set up the data needed by ExecVariableList. The slots in which the
- * variables can be found at runtime are denoted by the offsets of
- * their slot pointers within the econtext. This rather grotty
- * representation is needed because the caller may not have given us
- * the real econtext yet (see hacks in nodeSubplan.c).
- */
- foreach(tl, targetList)
+ if (isSimpleVar)
{
- GenericExprState *gstate = (GenericExprState *) lfirst(tl);
- Var *variable = (Var *) gstate->arg->expr;
- AttrNumber attnum = variable->varattno;
TargetEntry *tle = (TargetEntry *) gstate->xprstate.expr;
- AttrNumber resind = tle->resno - 1;
+ AttrNumber attnum = variable->varattno;
- Assert(resind >= 0 && resind < len);
- varNumbers[resind] = attnum;
+ varNumbers[numSimpleVars] = attnum;
+ varOutputCols[numSimpleVars] = tle->resno;
+ if (tle->resno != numSimpleVars+1)
+ directMap = false;
switch (variable->varno)
{
case INNER:
- varSlotOffsets[resind] = offsetof(ExprContext,
- ecxt_innertuple);
- lastInnerVar = Max(lastInnerVar, attnum);
+ varSlotOffsets[numSimpleVars] = offsetof(ExprContext,
+ ecxt_innertuple);
+ if (projInfo->pi_lastInnerVar < attnum)
+ projInfo->pi_lastInnerVar = attnum;
break;
case OUTER:
- varSlotOffsets[resind] = offsetof(ExprContext,
- ecxt_outertuple);
- lastOuterVar = Max(lastOuterVar, attnum);
+ varSlotOffsets[numSimpleVars] = offsetof(ExprContext,
+ ecxt_outertuple);
+ if (projInfo->pi_lastOuterVar < attnum)
+ projInfo->pi_lastOuterVar = attnum;
break;
default:
- varSlotOffsets[resind] = offsetof(ExprContext,
- ecxt_scantuple);
- lastScanVar = Max(lastScanVar, attnum);
+ varSlotOffsets[numSimpleVars] = offsetof(ExprContext,
+ ecxt_scantuple);
+ if (projInfo->pi_lastScanVar < attnum)
+ projInfo->pi_lastScanVar = attnum;
break;
}
+ numSimpleVars++;
+ }
+ else
+ {
+ /* Not a simple variable, add it to generic targetlist */
+ exprlist = lappend(exprlist, gstate);
+ /* Examine expr to include contained Vars in lastXXXVar counts */
+ get_last_attnums((Node *) variable, projInfo);
}
- projInfo->pi_lastInnerVar = lastInnerVar;
- projInfo->pi_lastOuterVar = lastOuterVar;
- projInfo->pi_lastScanVar = lastScanVar;
}
+ projInfo->pi_targetlist = exprlist;
+ projInfo->pi_numSimpleVars = numSimpleVars;
+ projInfo->pi_directMap = directMap;
+
+ if (exprlist == NIL)
+ projInfo->pi_itemIsDone = NULL; /* not needed */
else
- {
projInfo->pi_itemIsDone = (ExprDoneCond *)
palloc(len * sizeof(ExprDoneCond));
- projInfo->pi_varSlotOffsets = NULL;
- projInfo->pi_varNumbers = NULL;
- }
return projInfo;
}
+/*
+ * get_last_attnums: expression walker for ExecBuildProjectionInfo
+ *
+ * Update the lastXXXVar counts to be at least as large as the largest
+ * attribute numbers found in the expression
+ */
+static bool
+get_last_attnums(Node *node, ProjectionInfo *projInfo)
+{
+ if (node == NULL)
+ return false;
+ if (IsA(node, Var))
+ {
+ Var *variable = (Var *) node;
+ AttrNumber attnum = variable->varattno;
+
+ switch (variable->varno)
+ {
+ case INNER:
+ if (projInfo->pi_lastInnerVar < attnum)
+ projInfo->pi_lastInnerVar = attnum;
+ break;
+
+ case OUTER:
+ if (projInfo->pi_lastOuterVar < attnum)
+ projInfo->pi_lastOuterVar = attnum;
+ break;
+
+ default:
+ if (projInfo->pi_lastScanVar < attnum)
+ projInfo->pi_lastScanVar = attnum;
+ break;
+ }
+ return false;
+ }
+ /*
+ * Don't examine the arguments of Aggrefs or WindowFuncs, because those
+ * do not represent expressions to be evaluated within the overall
+ * targetlist's econtext.
+ */
+ if (IsA(node, Aggref))
+ return false;
+ if (IsA(node, WindowFunc))
+ return false;
+ return expression_tree_walker(node, get_last_attnums,
+ (void *) projInfo);
+}
+
/* ----------------
* ExecAssignProjectionInfo
*
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