Avoid REFREH fast path if matview has foreign tables.

For matview has foreign tables, we never know the data
status.
Since we usually create a matview has read external tables,
the initial data status is Up-to-date.
That will make REFRESH fail to do the real thing with
fast path feature, the worst case is we never try to get
the external data during REFRESH.

Authored-by: Zhang Mingli avamingli@gmail.com

src/backend/catalog/gp_matview_aux.c

@@ -50,7 +50,7 @@ static void SetMatviewAuxStatus_guts(Oid mvoid, char status);
  * Return NIL if the query we think it's useless.
  */
 List*
-GetViewBaseRelids(const Query *viewQuery)
+GetViewBaseRelids(const Query *viewQuery, bool *has_foreign)
 {
 	List	*relids = NIL;
 	Node	*mvjtnode;
@@ -100,6 +100,9 @@ GetViewBaseRelids(const Query *viewQuery)
 		relkind != RELKIND_FOREIGN_TABLE)
 		return NIL;
 
+	if (has_foreign)
+		*has_foreign = relkind == RELKIND_FOREIGN_TABLE;
+
 	/*
 	 * inherit tables are not supported.
 	 * FIXME: left a door for partition table which will be supported soon.
@@ -140,11 +143,12 @@ InsertMatviewAuxEntry(Oid mvoid, const Query *viewQuery, bool skipdata)
 	Datum		values[Natts_gp_matview_aux];
 	List 		*relids;
 	NameData	mvname;
+	bool		has_foreign = false;
 
 	Assert(OidIsValid(mvoid));
 
 	/* Empty relids means the view is not supported now. */
-	relids = GetViewBaseRelids(viewQuery);
+	relids = GetViewBaseRelids(viewQuery, &has_foreign);
 	if (relids == NIL)
 		return;
 
@@ -157,6 +161,8 @@ InsertMatviewAuxEntry(Oid mvoid, const Query *viewQuery, bool skipdata)
 
 	namestrcpy(&mvname, get_rel_name(mvoid));
 	values[Anum_gp_matview_aux_mvname - 1] = NameGetDatum(&mvname);
+
+	values[Anum_gp_matview_aux_has_foreign - 1] = BoolGetDatum(has_foreign);
 
 	if (skipdata)
 		values[Anum_gp_matview_aux_datastatus - 1] = CharGetDatum(MV_DATA_STATUS_EXPIRED);
@@ -449,6 +455,19 @@ MatviewUsableForAppendAgg(Oid mvoid)
 			(auxform->datastatus == MV_DATA_STATUS_EXPIRED_INSERT_ONLY));
 }
 
+bool
+MatviewHasForeignTables(Oid mvoid)
+{
+	HeapTuple mvauxtup = SearchSysCacheCopy1(MVAUXOID, ObjectIdGetDatum(mvoid));
+
+	/* Not a candidate we recorded. */
+	if (!HeapTupleIsValid(mvauxtup))
+		return false;
+
+	Form_gp_matview_aux auxform = (Form_gp_matview_aux) GETSTRUCT(mvauxtup);
+	return auxform->has_foreign;
+}
+
 /*
  * Is the view data up to date?
  * In most cases, we should use this function to check if view

src/backend/commands/matview.c

@@ -482,7 +482,8 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
 	if (gp_enable_refresh_fast_path &&
 		!RelationIsIVM(matviewRel) &&
 		!stmt->skipData &&
-		MatviewIsUpToDate(matviewOid))
+		MatviewIsUpToDate(matviewOid) &&
+		!MatviewHasForeignTables(matviewOid))
 	{
 		table_close(matviewRel, NoLock);
 

src/include/catalog/gp_matview_aux.h

@@ -27,6 +27,7 @@ CATALOG(gp_matview_aux,7153,GpMatviewAuxId) BKI_SHARED_RELATION
 {
 	Oid			mvoid; 	/* materialized view oid */
 	NameData	mvname; /* materialized view name */
+	bool		has_foreign;	/* view query has foreign tables? */
 	/* view's data status */
 	char		datastatus; 
 } FormData_gp_matview_aux;
@@ -57,12 +58,14 @@ extern void InsertMatviewAuxEntry(Oid mvoid, const Query *viewQuery, bool skipda
 
 extern void RemoveMatviewAuxEntry(Oid mvoid);
 
-extern List* GetViewBaseRelids(const Query *viewQuery);
+extern List* GetViewBaseRelids(const Query *viewQuery, bool *has_foreign);
 
 extern void SetRelativeMatviewAuxStatus(Oid relid, char status);
 
 extern void SetMatviewAuxStatus(Oid mvoid, char status);
 
+extern bool MatviewHasForeignTables(Oid mvoid);
+
 extern bool MatviewUsableForAppendAgg(Oid mvoid);
 
 extern bool MatviewIsGeneralyUpToDate(Oid mvoid);

src/test/regress/expected/aqumv.out

@@ -2682,6 +2682,52 @@ select * from aqumv_ext_r where id = 5;
   5
 (1 row)
 
+-- refresh matview has foreign tables should not go fast path. 
+select * from aqumv_ext_mv;
+ id 
+----
+  5
+  6
+  9
+ 10
+  2
+  3
+  4
+  7
+  8
+  1
+(10 rows)
+
+INSERT INTO aqumv_ext_w SELECT * FROM generate_series(10, 15);
+set local gp_enable_refresh_fast_path = on;
+select datastatus from gp_matview_aux where mvoid = 'aqumv_ext_mv'::regclass::oid;
+ datastatus 
+------------
+ u
+(1 row)
+
+refresh materialized view aqumv_ext_mv;
+select * from aqumv_ext_mv;
+ id 
+----
+  2
+  3
+  4
+  7
+  8
+  1
+ 12
+ 15
+  5
+  6
+  9
+ 10
+ 10
+ 11
+ 13
+ 14
+(16 rows)
+
 abort;
 --
 -- End of test external table

src/test/regress/sql/aqumv.sql

@@ -669,6 +669,13 @@ explain (costs off, verbose)
 select * from aqumv_ext_r where id = 5;
 select * from aqumv_ext_r where id = 5;
 
+-- refresh matview has foreign tables should not go fast path. 
+select * from aqumv_ext_mv;
+INSERT INTO aqumv_ext_w SELECT * FROM generate_series(10, 15);
+set local gp_enable_refresh_fast_path = on;
+select datastatus from gp_matview_aux where mvoid = 'aqumv_ext_mv'::regclass::oid;
+refresh materialized view aqumv_ext_mv;
+select * from aqumv_ext_mv;
 abort;
 --
 -- End of test external table