pgstatindex, pageinspect: handle partitioned indexes

Commit 8b08f7d4 failed to update these modules to at least give
non-broken error messages for partitioned indexes.  Add appropriate
error support to them.

Peter G. was complaining about a problem of unfriendly error messages;
while we haven't fixed that yet, subsequent discussion let to discovery
of these unhandled cases.

Author: Michaël Paquier
Reported-by: Peter Geoghegan
Discussion: https://postgr.es/m/CAH2-WzkOKptQiE51Bh4_xeEHhaBwHkZkGtKizrFMgEkfUuRRQg@mail.gmail.com

contrib/pageinspect/expected/page.out

@@ -83,10 +83,14 @@ SELECT * FROM fsm_page_contents(get_raw_page('test1', 'fsm', 0));
 (1 row)
 
 DROP TABLE test1;
--- check that using any of these functions with a partitioned table would fail
+-- check that using any of these functions with a partitioned table or index
+-- would fail
 create table test_partitioned (a int) partition by range (a);
+create index test_partitioned_index on test_partitioned (a);
 select get_raw_page('test_partitioned', 0); -- error about partitioned table
 ERROR:  cannot get raw page from partitioned table "test_partitioned"
+select get_raw_page('test_partitioned_index', 0); -- error about partitioned index
+ERROR:  cannot get raw page from partitioned index "test_partitioned_index"
 -- a regular table which is a member of a partition set should work though
 create table test_part1 partition of test_partitioned for values from ( 1 ) to (100);
 select get_raw_page('test_part1', 0); -- get farther and error about empty table

contrib/pageinspect/rawpage.c

@@ -128,6 +128,11 @@ get_raw_page_internal(text *relname, ForkNumber forknum, BlockNumber blkno)
 				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
 				 errmsg("cannot get raw page from partitioned table \"%s\"",
 						RelationGetRelationName(rel))));
+	if (rel->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot get raw page from partitioned index \"%s\"",
+						RelationGetRelationName(rel))));
 
 	/*
 	 * Reject attempts to read non-local temporary relations; we would be

contrib/pageinspect/sql/page.sql

@@ -33,9 +33,12 @@ SELECT * FROM fsm_page_contents(get_raw_page('test1', 'fsm', 0));
 
 DROP TABLE test1;
 
--- check that using any of these functions with a partitioned table would fail
+-- check that using any of these functions with a partitioned table or index
+-- would fail
 create table test_partitioned (a int) partition by range (a);
+create index test_partitioned_index on test_partitioned (a);
 select get_raw_page('test_partitioned', 0); -- error about partitioned table
+select get_raw_page('test_partitioned_index', 0); -- error about partitioned index
 
 -- a regular table which is a member of a partition set should work though
 create table test_part1 partition of test_partitioned for values from ( 1 ) to (100);

contrib/pgstattuple/expected/pgstattuple.out

@@ -152,9 +152,12 @@ select pgstatginindex('test_hashidx');
 ERROR:  relation "test_hashidx" is not a GIN index
 -- check that using any of these functions with unsupported relations will fail
 create table test_partitioned (a int) partition by range (a);
+create index test_partitioned_index on test_partitioned(a);
 -- these should all fail
 select pgstattuple('test_partitioned');
 ERROR:  "test_partitioned" (partitioned table) is not supported
+select pgstattuple('test_partitioned_index');
+ERROR:  "test_partitioned_index" (partitioned index) is not supported
 select pgstattuple_approx('test_partitioned');
 ERROR:  "test_partitioned" is not a table or materialized view
 select pg_relpages('test_partitioned');

contrib/pgstattuple/pgstatindex.c

@@ -604,7 +604,6 @@ pgstathashindex(PG_FUNCTION_ARGS)
 				 errmsg("relation \"%s\" is not a hash index",
 						RelationGetRelationName(rel))));
 
-
 	/*
 	 * Reject attempts to read non-local temporary relations; we would be
 	 * likely to get wrong data since we have no visibility into the owning

contrib/pgstattuple/pgstattuple.c

@@ -296,6 +296,9 @@ pgstat_relation(Relation rel, FunctionCallInfo fcinfo)
 		case RELKIND_PARTITIONED_TABLE:
 			err = "partitioned table";
 			break;
+		case RELKIND_PARTITIONED_INDEX:
+			err = "partitioned index";
+			break;
 		default:
 			err = "unknown";
 			break;

contrib/pgstattuple/sql/pgstattuple.sql

@@ -64,8 +64,10 @@ select pgstatginindex('test_hashidx');
 
 -- check that using any of these functions with unsupported relations will fail
 create table test_partitioned (a int) partition by range (a);
+create index test_partitioned_index on test_partitioned(a);
 -- these should all fail
 select pgstattuple('test_partitioned');
+select pgstattuple('test_partitioned_index');
 select pgstattuple_approx('test_partitioned');
 select pg_relpages('test_partitioned');
 select pgstatindex('test_partitioned');