Add relkind checks to certain contrib modules

The contrib extensions pageinspect, pg_visibility and pgstattuple only
work against regular relations which have storage.  They don't work
against foreign tables, partitioned (parent) tables, views, et al.

Add checks to the user-callable functions to return a useful error
message to the user if they mistakenly pass an invalid relation to a
function which doesn't accept that kind of relation.

In passing, improve some of the existing checks to use ereport() instead
of elog(), add a function to consolidate common checks where
appropriate, and add some regression tests.

Author: Amit Langote, with various changes by me
Reviewed by: Michael Paquier and Corey Huinker
Discussion: https://postgr.es/m/ab91fd9d-4751-ee77-c87b-4dd704c1e59c@lab.ntt.co.jp

1 files changed, 64 insertions, 0 deletions

diff --git a/contrib/pgstattuple/sql/pgstattuple.sql b/contrib/pgstattuple/sql/pgstattuple.sql
index 81fd5d693b4..25a0daa3312 100644
--- a/contrib/pgstattuple/sql/pgstattuple.sql
+++ b/contrib/pgstattuple/sql/pgstattuple.sql
@@ -51,3 +51,67 @@ select * from pgstatginindex('test_ginidx');
 create index test_hashidx on test using hash (b);
 
 select * from pgstathashindex('test_hashidx');
+
+-- these should error with the wrong type
+select pgstatginindex('test_pkey');
+select pgstathashindex('test_pkey');
+
+select pgstatindex('test_ginidx');
+select pgstathashindex('test_ginidx');
+
+select pgstatindex('test_hashidx');
+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);
+-- these should all fail
+select pgstattuple('test_partitioned');
+select pgstattuple_approx('test_partitioned');
+select pg_relpages('test_partitioned');
+select pgstatindex('test_partitioned');
+select pgstatginindex('test_partitioned');
+select pgstathashindex('test_partitioned');
+
+create view test_view as select 1;
+-- these should all fail
+select pgstattuple('test_view');
+select pgstattuple_approx('test_view');
+select pg_relpages('test_view');
+select pgstatindex('test_view');
+select pgstatginindex('test_view');
+select pgstathashindex('test_view');
+
+create foreign data wrapper dummy;
+create server dummy_server foreign data wrapper dummy;
+create foreign table test_foreign_table () server dummy_server;
+-- these should all fail
+select pgstattuple('test_foreign_table');
+select pgstattuple_approx('test_foreign_table');
+select pg_relpages('test_foreign_table');
+select pgstatindex('test_foreign_table');
+select pgstatginindex('test_foreign_table');
+select pgstathashindex('test_foreign_table');
+
+-- a partition of a partitioned table should work though
+create table test_partition partition of test_partitioned for values from (1) to (100);
+select pgstattuple('test_partition');
+select pgstattuple_approx('test_partition');
+select pg_relpages('test_partition');
+
+-- not for the index calls though, of course
+select pgstatindex('test_partition');
+select pgstatginindex('test_partition');
+select pgstathashindex('test_partition');
+
+-- an actual index of a partitiond table should work though
+create index test_partition_idx on test_partition(a);
+create index test_partition_hash_idx on test_partition using hash (a);
+-- these should work
+select pgstatindex('test_partition_idx');
+select pgstathashindex('test_partition_hash_idx');
+
+drop table test_partitioned;
+drop view test_view;
+drop foreign table test_foreign_table;
+drop server dummy_server;
+drop foreign data wrapper dummy;