From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Wed, 28 Jan 2004 00:05:25 +0000 (+0000)
Subject: simplify_function() mustn't try to evaluate functions that return
X-Git-Tag: REL7_4_2~52
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9f017115f598ad3e900f383dac17ff8463075d1e;p=postgresql

simplify_function() mustn't try to evaluate functions that return
composite types, because TupleTableSlots aren't Datums and can't be
stored in Const nodes.  We can remove this restriction if we ever
adopt a cleaner runtime representation for whole-tuple results, but
at the moment it's broken.  Per example from Thomas Hallgren.
---

diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 688e106f4e..d8809a5252 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.154.2.1 2003/12/09 01:56:41 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.154.2.2 2004/01/28 00:05:25 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -1655,6 +1655,7 @@ evaluate_function(Oid funcid, Oid result_type, List *args,
 	bool		has_null_input = false;
 	List	   *arg;
 	FuncExpr   *newexpr;
+	char		result_typtype;
 
 	/*
 	 * Can't simplify if it returns a set.
@@ -1691,6 +1692,15 @@ evaluate_function(Oid funcid, Oid result_type, List *args,
 		has_nonconst_input)
 		return NULL;
 
+	/*
+	 * Can't simplify functions returning composite types (mainly because
+	 * datumCopy() doesn't cope; FIXME someday when we have a saner
+	 * representation for whole-tuple results).
+	 */
+	result_typtype = get_typtype(funcform->prorettype);
+	if (result_typtype == 'c')
+		return NULL;
+
 	/*
 	 * OK, looks like we can simplify this operator/function.
 	 *