Rethink function argument sorting in pg_dump.

Commit 7b583b2 created an unnecessary
dump failure hazard by applying pg_get_function_identity_arguments()
to every function in the database, even those that won't get dumped.
This could result in snapshot-related problems if concurrent sessions are,
for example, creating and dropping temporary functions, as noted by Marko
Tiikkaja in bug #12832.  While this is by no means pg_dump's only such
issue with concurrent DDL, it's unfortunate that we added a new failure
mode for cases that used to work, and even more so that the failure was
created for basically cosmetic reasons (ie, to sort overloaded functions
more deterministically).

To fix, revert that patch and instead sort function arguments using
information that pg_dump has available anyway, namely the names of the
argument types.  This will produce a slightly different sort ordering for
overloaded functions than the previous coding; but applying strcmp
directly to the output of pg_get_function_identity_arguments really was
a bit odd anyway.  The sorting will still be name-based and hence
independent of possibly-installation-specific OID assignments.  A small
additional benefit is that sorting now works regardless of server version.

Back-patch to 9.3, where the previous commit appeared.

Author: tglsfdc

src/bin/pg_dump/pg_dump.c

@@ -3912,7 +3912,6 @@ getAggregates(Archive *fout, int *numAggs)
 	int			i_proargtypes;
 	int			i_rolname;
 	int			i_aggacl;
-	int			i_proiargs;
 
 	/* Make sure we are in proper schema */
 	selectSourceSchema(fout, "pg_catalog");
@@ -3922,12 +3921,11 @@ getAggregates(Archive *fout, int *numAggs)
 	 * rationale behind the filtering logic.
 	 */
 
-	if (fout->remoteVersion >= 80400)
+	if (fout->remoteVersion >= 80200)
 	{
 		appendPQExpBuffer(query, "SELECT tableoid, oid, proname AS aggname, "
 						  "pronamespace AS aggnamespace, "
 						  "pronargs, proargtypes, "
-			"pg_catalog.pg_get_function_identity_arguments(oid) AS proiargs,"
 						  "(%s proowner) AS rolname, "
 						  "proacl AS aggacl "
 						  "FROM pg_proc p "
@@ -3945,28 +3943,12 @@ getAggregates(Archive *fout, int *numAggs)
 							  "deptype = 'e')");
 		appendPQExpBuffer(query, ")");
 	}
-	else if (fout->remoteVersion >= 80200)
-	{
-		appendPQExpBuffer(query, "SELECT tableoid, oid, proname AS aggname, "
-						  "pronamespace AS aggnamespace, "
-						  "pronargs, proargtypes, "
-						  "NULL::text AS proiargs,"
-						  "(%s proowner) AS rolname, "
-						  "proacl AS aggacl "
-						  "FROM pg_proc p "
-						  "WHERE proisagg AND ("
-						  "pronamespace != "
-						  "(SELECT oid FROM pg_namespace "
-						  "WHERE nspname = 'pg_catalog'))",
-						  username_subquery);
-	}
 	else if (fout->remoteVersion >= 70300)
 	{
 		appendPQExpBuffer(query, "SELECT tableoid, oid, proname AS aggname, "
 						  "pronamespace AS aggnamespace, "
 						  "CASE WHEN proargtypes[0] = 'pg_catalog.\"any\"'::pg_catalog.regtype THEN 0 ELSE 1 END AS pronargs, "
 						  "proargtypes, "
-						  "NULL::text AS proiargs, "
 						  "(%s proowner) AS rolname, "
 						  "proacl AS aggacl "
 						  "FROM pg_proc "
@@ -3981,7 +3963,6 @@ getAggregates(Archive *fout, int *numAggs)
 						  "0::oid AS aggnamespace, "
 				  "CASE WHEN aggbasetype = 0 THEN 0 ELSE 1 END AS pronargs, "
 						  "aggbasetype AS proargtypes, "
-						  "NULL::text AS proiargs, "
 						  "(%s aggowner) AS rolname, "
 						  "'{=X}' AS aggacl "
 						  "FROM pg_aggregate "
@@ -3997,7 +3978,6 @@ getAggregates(Archive *fout, int *numAggs)
 						  "0::oid AS aggnamespace, "
 				  "CASE WHEN aggbasetype = 0 THEN 0 ELSE 1 END AS pronargs, "
 						  "aggbasetype AS proargtypes, "
-						  "NULL::text AS proiargs, "
 						  "(%s aggowner) AS rolname, "
 						  "'{=X}' AS aggacl "
 						  "FROM pg_aggregate "
@@ -4021,7 +4001,6 @@ getAggregates(Archive *fout, int *numAggs)
 	i_proargtypes = PQfnumber(res, "proargtypes");
 	i_rolname = PQfnumber(res, "rolname");
 	i_aggacl = PQfnumber(res, "aggacl");
-	i_proiargs = PQfnumber(res, "proiargs");
 
 	for (i = 0; i < ntups; i++)
 	{
@@ -4041,7 +4020,6 @@ getAggregates(Archive *fout, int *numAggs)
 		agginfo[i].aggfn.lang = InvalidOid;		/* not currently interesting */
 		agginfo[i].aggfn.prorettype = InvalidOid;		/* not saved */
 		agginfo[i].aggfn.proacl = pg_strdup(PQgetvalue(res, i, i_aggacl));
-		agginfo[i].aggfn.proiargs = pg_strdup(PQgetvalue(res, i, i_proiargs));
 		agginfo[i].aggfn.nargs = atoi(PQgetvalue(res, i, i_pronargs));
 		if (agginfo[i].aggfn.nargs == 0)
 			agginfo[i].aggfn.argtypes = NULL;
@@ -4093,7 +4071,6 @@ getFuncs(Archive *fout, int *numFuncs)
 	int			i_proargtypes;
 	int			i_prorettype;
 	int			i_proacl;
-	int			i_proiargs;
 
 	/* Make sure we are in proper schema */
 	selectSourceSchema(fout, "pg_catalog");
@@ -4114,13 +4091,12 @@ getFuncs(Archive *fout, int *numFuncs)
 	 * doesn't have; otherwise we might not get creation ordering correct.
 	 */
 
-	if (fout->remoteVersion >= 80400)
+	if (fout->remoteVersion >= 70300)
 	{
 		appendPQExpBuffer(query,
 						  "SELECT tableoid, oid, proname, prolang, "
 						  "pronargs, proargtypes, prorettype, proacl, "
 						  "pronamespace, "
-			"pg_catalog.pg_get_function_identity_arguments(oid) AS proiargs,"
 						  "(%s proowner) AS rolname "
 						  "FROM pg_proc p "
 						  "WHERE NOT proisagg AND ("
@@ -4142,29 +4118,13 @@ getFuncs(Archive *fout, int *numFuncs)
 							  "deptype = 'e')");
 		appendPQExpBuffer(query, ")");
 	}
-	else if (fout->remoteVersion >= 70300)
-	{
-		appendPQExpBuffer(query,
-						  "SELECT tableoid, oid, proname, prolang, "
-						  "pronargs, proargtypes, prorettype, proacl, "
-						  "pronamespace, "
-						  "NULL::text AS proiargs,"
-						  "(%s proowner) AS rolname "
-						  "FROM pg_proc p "
-						  "WHERE NOT proisagg AND ("
-						  "pronamespace != "
-						  "(SELECT oid FROM pg_namespace "
-						  "WHERE nspname = 'pg_catalog'))",
-						  username_subquery);
-	}
 	else if (fout->remoteVersion >= 70100)
 	{
 		appendPQExpBuffer(query,
 						  "SELECT tableoid, oid, proname, prolang, "
 						  "pronargs, proargtypes, prorettype, "
 						  "'{=X}' AS proacl, "
 						  "0::oid AS pronamespace, "
-						  "NULL::text AS proiargs,"
 						  "(%s proowner) AS rolname "
 						  "FROM pg_proc "
 						  "WHERE pg_proc.oid > '%u'::oid",
@@ -4181,7 +4141,6 @@ getFuncs(Archive *fout, int *numFuncs)
 						  "pronargs, proargtypes, prorettype, "
 						  "'{=X}' AS proacl, "
 						  "0::oid AS pronamespace, "
-						  "NULL::text AS proiargs,"
 						  "(%s proowner) AS rolname "
 						  "FROM pg_proc "
 						  "where pg_proc.oid > '%u'::oid",
@@ -4207,7 +4166,6 @@ getFuncs(Archive *fout, int *numFuncs)
 	i_proargtypes = PQfnumber(res, "proargtypes");
 	i_prorettype = PQfnumber(res, "prorettype");
 	i_proacl = PQfnumber(res, "proacl");
-	i_proiargs = PQfnumber(res, "proiargs");
 
 	for (i = 0; i < ntups; i++)
 	{
@@ -4223,7 +4181,6 @@ getFuncs(Archive *fout, int *numFuncs)
 		finfo[i].rolname = pg_strdup(PQgetvalue(res, i, i_rolname));
 		finfo[i].lang = atooid(PQgetvalue(res, i, i_prolang));
 		finfo[i].prorettype = atooid(PQgetvalue(res, i, i_prorettype));
-		finfo[i].proiargs = pg_strdup(PQgetvalue(res, i, i_proiargs));
 		finfo[i].proacl = pg_strdup(PQgetvalue(res, i, i_proacl));
 		finfo[i].nargs = atoi(PQgetvalue(res, i, i_pronargs));
 		if (finfo[i].nargs == 0)

src/bin/pg_dump/pg_dump.h

@@ -184,7 +184,6 @@ typedef struct _funcInfo
 	Oid		   *argtypes;
 	Oid			prorettype;
 	char	   *proacl;
-	char	   *proiargs;
 } FuncInfo;
 
 /* AggInfo is a superset of FuncInfo */

src/bin/pg_dump/pg_dump_sort.c

@@ -287,13 +287,30 @@ DOTypeNameCompare(const void *p1, const void *p2)
 	{
 		FuncInfo   *fobj1 = *(FuncInfo *const *) p1;
 		FuncInfo   *fobj2 = *(FuncInfo *const *) p2;
+		int			i;
 
 		cmpval = fobj1->nargs - fobj2->nargs;
 		if (cmpval != 0)
 			return cmpval;
-		cmpval = strcmp(fobj1->proiargs, fobj2->proiargs);
-		if (cmpval != 0)
-			return cmpval;
+		for (i = 0; i < fobj1->nargs; i++)
+		{
+			TypeInfo   *argtype1 = findTypeByOid(fobj1->argtypes[i]);
+			TypeInfo   *argtype2 = findTypeByOid(fobj2->argtypes[i]);
+
+			if (argtype1 && argtype2)
+			{
+				if (argtype1->dobj.namespace && argtype2->dobj.namespace)
+				{
+					cmpval = strcmp(argtype1->dobj.namespace->dobj.name,
+									argtype2->dobj.namespace->dobj.name);
+					if (cmpval != 0)
+						return cmpval;
+				}
+				cmpval = strcmp(argtype1->dobj.name, argtype2->dobj.name);
+				if (cmpval != 0)
+					return cmpval;
+			}
+		}
 	}
 	else if (obj1->objType == DO_OPERATOR)
 	{