Stats: use schemaname/relname instead of regclass.

For import and export, use schemaname/relname rather than
regclass.

This is more natural during export, fits with the other arguments
better, and it gives better control over error handling in case we
need to downgrade more errors to warnings.

Also, use text for the argument types for schemaname, relname, and
attname so that casts to "name" are not required.

Author: Corey Huinker <corey.huinker@gmail.com>
Discussion: https://postgr.es/m/CADkLM=ceOSsx_=oe73QQ-BxUFR2Cwqum7-UP_fPe22DBY0NerA@mail.gmail.com

src/backend/statistics/attribute_stats.c

@@ -36,7 +36,8 @@
 
 enum attribute_stats_argnum
 {
-	ATTRELATION_ARG = 0,
+	ATTRELSCHEMA_ARG = 0,
+	ATTRELNAME_ARG,
 	ATTNAME_ARG,
 	ATTNUM_ARG,
 	INHERITED_ARG,
@@ -58,8 +59,9 @@ enum attribute_stats_argnum
 
 static struct StatsArgInfo attarginfo[] =
 {
-	[ATTRELATION_ARG] = {"relation", REGCLASSOID},
-	[ATTNAME_ARG] = {"attname", NAMEOID},
+	[ATTRELSCHEMA_ARG] = {"schemaname", TEXTOID},
+	[ATTRELNAME_ARG] = {"relname", TEXTOID},
+	[ATTNAME_ARG] = {"attname", TEXTOID},
 	[ATTNUM_ARG] = {"attnum", INT2OID},
 	[INHERITED_ARG] = {"inherited", BOOLOID},
 	[NULL_FRAC_ARG] = {"null_frac", FLOAT4OID},
@@ -80,7 +82,8 @@ static struct StatsArgInfo attarginfo[] =
 
 enum clear_attribute_stats_argnum
 {
-	C_ATTRELATION_ARG = 0,
+	C_ATTRELSCHEMA_ARG = 0,
+	C_ATTRELNAME_ARG,
 	C_ATTNAME_ARG,
 	C_INHERITED_ARG,
 	C_NUM_ATTRIBUTE_STATS_ARGS
@@ -88,8 +91,9 @@ enum clear_attribute_stats_argnum
 
 static struct StatsArgInfo cleararginfo[] =
 {
-	[C_ATTRELATION_ARG] = {"relation", REGCLASSOID},
-	[C_ATTNAME_ARG] = {"attname", NAMEOID},
+	[C_ATTRELSCHEMA_ARG] = {"relation", TEXTOID},
+	[C_ATTRELNAME_ARG] = {"relation", TEXTOID},
+	[C_ATTNAME_ARG] = {"attname", TEXTOID},
 	[C_INHERITED_ARG] = {"inherited", BOOLOID},
 	[C_NUM_ATTRIBUTE_STATS_ARGS] = {0}
 };
@@ -133,6 +137,8 @@ static void init_empty_stats_tuple(Oid reloid, int16 attnum, bool inherited,
 static bool
 attribute_statistics_update(FunctionCallInfo fcinfo)
 {
+	char	   *nspname;
+	char	   *relname;
 	Oid			reloid;
 	char	   *attname;
 	AttrNumber	attnum;
@@ -170,8 +176,13 @@ attribute_statistics_update(FunctionCallInfo fcinfo)
 
 	bool		result = true;
 
-	stats_check_required_arg(fcinfo, attarginfo, ATTRELATION_ARG);
-	reloid = PG_GETARG_OID(ATTRELATION_ARG);
+	stats_check_required_arg(fcinfo, attarginfo, ATTRELSCHEMA_ARG);
+	stats_check_required_arg(fcinfo, attarginfo, ATTRELNAME_ARG);
+
+	nspname = TextDatumGetCString(PG_GETARG_DATUM(ATTRELSCHEMA_ARG));
+	relname = TextDatumGetCString(PG_GETARG_DATUM(ATTRELNAME_ARG));
+
+	reloid = stats_lookup_relid(nspname, relname);
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -185,21 +196,18 @@ attribute_statistics_update(FunctionCallInfo fcinfo)
 	/* user can specify either attname or attnum, but not both */
 	if (!PG_ARGISNULL(ATTNAME_ARG))
 	{
-		Name		attnamename;
-
 		if (!PG_ARGISNULL(ATTNUM_ARG))
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("cannot specify both attname and attnum")));
-		attnamename = PG_GETARG_NAME(ATTNAME_ARG);
-		attname = NameStr(*attnamename);
+		attname = TextDatumGetCString(PG_GETARG_DATUM(ATTNAME_ARG));
 		attnum = get_attnum(reloid, attname);
 		/* note that this test covers attisdropped cases too: */
 		if (attnum == InvalidAttrNumber)
 			ereport(ERROR,
 					(errcode(ERRCODE_UNDEFINED_COLUMN),
 					 errmsg("column \"%s\" of relation \"%s\" does not exist",
-							attname, get_rel_name(reloid))));
+							attname, relname)));
 	}
 	else if (!PG_ARGISNULL(ATTNUM_ARG))
 	{
@@ -211,7 +219,7 @@ attribute_statistics_update(FunctionCallInfo fcinfo)
 			ereport(ERROR,
 					(errcode(ERRCODE_UNDEFINED_COLUMN),
 					 errmsg("column %d of relation \"%s\" does not exist",
-							attnum, get_rel_name(reloid))));
+							attnum, relname)));
 	}
 	else
 	{
@@ -900,13 +908,22 @@ init_empty_stats_tuple(Oid reloid, int16 attnum, bool inherited,
 Datum
 pg_clear_attribute_stats(PG_FUNCTION_ARGS)
 {
+	char	   *nspname;
+	char	   *relname;
 	Oid			reloid;
-	Name		attname;
+	char	   *attname;
 	AttrNumber	attnum;
 	bool		inherited;
 
-	stats_check_required_arg(fcinfo, cleararginfo, C_ATTRELATION_ARG);
-	reloid = PG_GETARG_OID(C_ATTRELATION_ARG);
+	stats_check_required_arg(fcinfo, cleararginfo, C_ATTRELSCHEMA_ARG);
+	stats_check_required_arg(fcinfo, cleararginfo, C_ATTRELNAME_ARG);
+	stats_check_required_arg(fcinfo, cleararginfo, C_ATTNAME_ARG);
+	stats_check_required_arg(fcinfo, cleararginfo, C_INHERITED_ARG);
+
+	nspname = TextDatumGetCString(PG_GETARG_DATUM(C_ATTRELSCHEMA_ARG));
+	relname = TextDatumGetCString(PG_GETARG_DATUM(C_ATTRELNAME_ARG));
+
+	reloid = stats_lookup_relid(nspname, relname);
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -916,23 +933,21 @@ pg_clear_attribute_stats(PG_FUNCTION_ARGS)
 
 	stats_lock_check_privileges(reloid);
 
-	stats_check_required_arg(fcinfo, cleararginfo, C_ATTNAME_ARG);
-	attname = PG_GETARG_NAME(C_ATTNAME_ARG);
-	attnum = get_attnum(reloid, NameStr(*attname));
+	attname = TextDatumGetCString(PG_GETARG_DATUM(C_ATTNAME_ARG));
+	attnum = get_attnum(reloid, attname);
 
 	if (attnum < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("cannot clear statistics on system column \"%s\"",
-						NameStr(*attname))));
+						attname)));
 
 	if (attnum == InvalidAttrNumber)
 		ereport(ERROR,
 				(errcode(ERRCODE_UNDEFINED_COLUMN),
 				 errmsg("column \"%s\" of relation \"%s\" does not exist",
-						NameStr(*attname), get_rel_name(reloid))));
+						attname, get_rel_name(reloid))));
 
-	stats_check_required_arg(fcinfo, cleararginfo, C_INHERITED_ARG);
 	inherited = PG_GETARG_BOOL(C_INHERITED_ARG);
 
 	delete_pg_statistic(reloid, attnum, inherited);

src/backend/statistics/relation_stats.c

@@ -19,9 +19,12 @@
 
 #include "access/heapam.h"
 #include "catalog/indexing.h"
+#include "catalog/namespace.h"
 #include "statistics/stat_utils.h"
+#include "utils/builtins.h"
 #include "utils/fmgroids.h"
 #include "utils/fmgrprotos.h"
+#include "utils/lsyscache.h"
 #include "utils/syscache.h"
 
 
@@ -32,7 +35,8 @@
 
 enum relation_stats_argnum
 {
-	RELATION_ARG = 0,
+	RELSCHEMA_ARG = 0,
+	RELNAME_ARG,
 	RELPAGES_ARG,
 	RELTUPLES_ARG,
 	RELALLVISIBLE_ARG,
@@ -42,7 +46,8 @@ enum relation_stats_argnum
 
 static struct StatsArgInfo relarginfo[] =
 {
-	[RELATION_ARG] = {"relation", REGCLASSOID},
+	[RELSCHEMA_ARG] = {"schemaname", TEXTOID},
+	[RELNAME_ARG] = {"relname", TEXTOID},
 	[RELPAGES_ARG] = {"relpages", INT4OID},
 	[RELTUPLES_ARG] = {"reltuples", FLOAT4OID},
 	[RELALLVISIBLE_ARG] = {"relallvisible", INT4OID},
@@ -59,6 +64,8 @@ static bool
 relation_statistics_update(FunctionCallInfo fcinfo)
 {
 	bool		result = true;
+	char	   *nspname;
+	char	   *relname;
 	Oid			reloid;
 	Relation	crel;
 	BlockNumber relpages = 0;
@@ -76,6 +83,22 @@ relation_statistics_update(FunctionCallInfo fcinfo)
 	bool		nulls[4] = {0};
 	int			nreplaces = 0;
 
+	stats_check_required_arg(fcinfo, relarginfo, RELSCHEMA_ARG);
+	stats_check_required_arg(fcinfo, relarginfo, RELNAME_ARG);
+
+	nspname = TextDatumGetCString(PG_GETARG_DATUM(RELSCHEMA_ARG));
+	relname = TextDatumGetCString(PG_GETARG_DATUM(RELNAME_ARG));
+
+	reloid = stats_lookup_relid(nspname, relname);
+
+	if (RecoveryInProgress())
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("recovery is in progress"),
+				 errhint("Statistics cannot be modified during recovery.")));
+
+	stats_lock_check_privileges(reloid);
+
 	if (!PG_ARGISNULL(RELPAGES_ARG))
 	{
 		relpages = PG_GETARG_UINT32(RELPAGES_ARG);
@@ -108,17 +131,6 @@ relation_statistics_update(FunctionCallInfo fcinfo)
 		update_relallfrozen = true;
 	}
 
-	stats_check_required_arg(fcinfo, relarginfo, RELATION_ARG);
-	reloid = PG_GETARG_OID(RELATION_ARG);
-
-	if (RecoveryInProgress())
-		ereport(ERROR,
-				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-				 errmsg("recovery is in progress"),
-				 errhint("Statistics cannot be modified during recovery.")));
-
-	stats_lock_check_privileges(reloid);
-
 	/*
 	 * Take RowExclusiveLock on pg_class, consistent with
 	 * vac_update_relstats().
@@ -187,20 +199,22 @@ relation_statistics_update(FunctionCallInfo fcinfo)
 Datum
 pg_clear_relation_stats(PG_FUNCTION_ARGS)
 {
-	LOCAL_FCINFO(newfcinfo, 5);
+	LOCAL_FCINFO(newfcinfo, 6);
 
-	InitFunctionCallInfoData(*newfcinfo, NULL, 5, InvalidOid, NULL, NULL);
+	InitFunctionCallInfoData(*newfcinfo, NULL, 6, InvalidOid, NULL, NULL);
 
-	newfcinfo->args[0].value = PG_GETARG_OID(0);
+	newfcinfo->args[0].value = PG_GETARG_DATUM(0);
 	newfcinfo->args[0].isnull = PG_ARGISNULL(0);
-	newfcinfo->args[1].value = UInt32GetDatum(0);
-	newfcinfo->args[1].isnull = false;
-	newfcinfo->args[2].value = Float4GetDatum(-1.0);
+	newfcinfo->args[1].value = PG_GETARG_DATUM(1);
+	newfcinfo->args[1].isnull = PG_ARGISNULL(1);
+	newfcinfo->args[2].value = UInt32GetDatum(0);
 	newfcinfo->args[2].isnull = false;
-	newfcinfo->args[3].value = UInt32GetDatum(0);
+	newfcinfo->args[3].value = Float4GetDatum(-1.0);
 	newfcinfo->args[3].isnull = false;
 	newfcinfo->args[4].value = UInt32GetDatum(0);
 	newfcinfo->args[4].isnull = false;
+	newfcinfo->args[5].value = UInt32GetDatum(0);
+	newfcinfo->args[5].isnull = false;
 
 	relation_statistics_update(newfcinfo);
 	PG_RETURN_VOID();

src/backend/statistics/stat_utils.c

@@ -18,6 +18,7 @@
 
 #include "access/relation.h"
 #include "catalog/index.h"
+#include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "funcapi.h"
 #include "miscadmin.h"
@@ -213,6 +214,27 @@ stats_lock_check_privileges(Oid reloid)
 	relation_close(table, NoLock);
 }
 
+/*
+ * Lookup relation oid from schema and relation name.
+ */
+Oid
+stats_lookup_relid(const char *nspname, const char *relname)
+{
+	Oid			nspoid;
+	Oid			reloid;
+
+	nspoid = LookupExplicitNamespace(nspname, false);
+	reloid = get_relname_relid(relname, nspoid);
+	if (!OidIsValid(reloid))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_TABLE),
+				 errmsg("relation \"%s.%s\" does not exist",
+						nspname, relname)));
+
+	return reloid;
+}
+
+
 /*
  * Find the argument number for the given argument name, returning -1 if not
  * found.