postgres
diff --git a/‎src/backend/parser/parse_relation.c
Lines changed: 32 additions & 3 deletions b/‎src/backend/parser/parse_relation.c
Lines changed: 32 additions & 3 deletions
@@ -1830,8 +1830,16 @@ addRangeTableEntryForFunction(ParseState *pstate,
 
 			/*
 			 * Use the column definition list to construct a tupdesc and fill
-			 * in the RangeTblFunction's lists.
+			 * in the RangeTblFunction's lists.  Limit number of columns to
+			 * MaxHeapAttributeNumber, because CheckAttributeNamesTypes will.
 			 */
+			if (list_length(coldeflist) > MaxHeapAttributeNumber)
+				ereport(ERROR,
+						(errcode(ERRCODE_TOO_MANY_COLUMNS),
+						 errmsg("column definition lists can have at most %d entries",
+								MaxHeapAttributeNumber),
+						 parser_errposition(pstate,
+											exprLocation((Node *) coldeflist))));
 			tupdesc = CreateTemplateTupleDesc(list_length(coldeflist));
 			i = 1;
 			foreach(col, coldeflist)
@@ -1911,6 +1919,15 @@ addRangeTableEntryForFunction(ParseState *pstate,
 		if (rangefunc->ordinality)
 			totalatts++;
 
+		/* Disallow more columns than will fit in a tuple */
+		if (totalatts > MaxTupleAttributeNumber)
+			ereport(ERROR,
+					(errcode(ERRCODE_TOO_MANY_COLUMNS),
+					 errmsg("functions in FROM can return at most %d columns",
+							MaxTupleAttributeNumber),
+					 parser_errposition(pstate,
+										exprLocation((Node *) funcexprs))));
+
 		/* Merge the tuple descs of each function into a composite one */
 		tupdesc = CreateTemplateTupleDesc(totalatts);
 		natts = 0;
@@ -1993,11 +2010,23 @@ addRangeTableEntryForTableFunc(ParseState *pstate,
 	Alias	   *eref;
 	int			numaliases;
 
+	Assert(pstate != NULL);
+
+	/* Disallow more columns than will fit in a tuple */
+	if (list_length(tf->colnames) > MaxTupleAttributeNumber)
+		ereport(ERROR,
+				(errcode(ERRCODE_TOO_MANY_COLUMNS),
+				 errmsg("functions in FROM can return at most %d columns",
+						MaxTupleAttributeNumber),
+				 parser_errposition(pstate,
+									exprLocation((Node *) tf))));
+	Assert(list_length(tf->coltypes) == list_length(tf->colnames));
+	Assert(list_length(tf->coltypmods) == list_length(tf->colnames));
+	Assert(list_length(tf->colcollations) == list_length(tf->colnames));
+
 	refname = alias ? alias->aliasname :
 		pstrdup(tf->functype == TFT_XMLTABLE ? "xmltable" : "json_table");
 
-	Assert(pstate != NULL);
-
 	rte->rtekind = RTE_TABLEFUNC;
 	rte->relid = InvalidOid;
 	rte->subquery = NULL;