Phase 2 of read-only-plans project: restructure expression-tree nodes

so that all executable expression nodes inherit from a common supertype
Expr.  This is somewhat of an exercise in code purity rather than any
real functional advance, but getting rid of the extra Oper or Func node
formerly used in each operator or function call should provide at least
a little space and speed improvement.
initdb forced by changes in stored-rules representation.

1 files changed, 20 insertions, 13 deletions

diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 0b5efaa319e..c587765bd5a 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -5,7 +5,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994-5, Regents of the University of California
  *
- * $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.95 2002/12/06 19:28:03 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.96 2002/12/12 15:49:24 tgl Exp $
  *
  */
 
@@ -417,20 +417,27 @@ explain_outNode(StringInfo str,
 			{
 				RangeTblEntry *rte = rt_fetch(((Scan *) plan)->scanrelid,
 											  es->rtable);
-				Expr	   *expr;
-				Func	   *funcnode;
-				Oid			funcid;
 				char	   *proname;
 
 				/* Assert it's on a RangeFunction */
 				Assert(rte->rtekind == RTE_FUNCTION);
 
-				expr = (Expr *) rte->funcexpr;
-				funcnode = (Func *) expr->oper;
-				funcid = funcnode->funcid;
-
-				/* We only show the func name, not schema name */
-				proname = get_func_name(funcid);
+				/*
+				 * If the expression is still a function call, we can get
+				 * the real name of the function.  Otherwise, punt (this
+				 * can happen if the optimizer simplified away the function
+				 * call, for example).
+				 */
+				if (rte->funcexpr && IsA(rte->funcexpr, FuncExpr))
+				{
+					FuncExpr   *funcexpr = (FuncExpr *) rte->funcexpr;
+					Oid			funcid = funcexpr->funcid;
+
+					/* We only show the func name, not schema name */
+					proname = get_func_name(funcid);
+				}
+				else
+					proname = rte->eref->aliasname;
 
 				appendStringInfo(str, " on %s",
 								 quote_identifier(proname));
@@ -583,7 +590,7 @@ explain_outNode(StringInfo str,
 		appendStringInfo(str, "  InitPlan\n");
 		foreach(lst, plan->initPlan)
 		{
-			SubPlan	   *subplan = (SubPlan *) lfirst(lst);
+			SubPlanExpr  *subplan = (SubPlanExpr *) lfirst(lst);
 			SubPlanState *subplanstate = (SubPlanState *) lfirst(pslist);
 
 			es->rtable = subplan->rtable;
@@ -683,7 +690,7 @@ explain_outNode(StringInfo str,
 		foreach(lst, planstate->subPlan)
 		{
 			SubPlanState *sps = (SubPlanState *) lfirst(lst);
-			SubPlan *sp = (SubPlan *) sps->ps.plan;
+			SubPlanExpr *sp = (SubPlanExpr *) sps->ps.plan;
 
 			es->rtable = sp->rtable;
 			for (i = 0; i < indent; i++)
@@ -870,7 +877,7 @@ show_sort_keys(List *tlist, int nkeys, const char *qlabel,
 			if (target->resdom->reskey == keyno)
 			{
 				/* Deparse the expression, showing any top-level cast */
-				exprstr = deparse_expression(target->expr, context,
+				exprstr = deparse_expression((Node *) target->expr, context,
 											 useprefix, true);
 				/* And add to str */
 				if (keyno > 1)