CREATE EXTENSION pgstattuple;
--
-- It's difficult to come up with platform-independent test cases for
-- the pgstattuple functions, but the results for empty tables and
-- indexes should be that.
--
create table test (a int primary key);
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "test_pkey" for table "test"
select * from pgstattuple('test'::text);
 table_len | tuple_count | tuple_len | tuple_percent | dead_tuple_count | dead_tuple_len | dead_tuple_percent | free_space | free_percent 
-----------+-------------+-----------+---------------+------------------+----------------+--------------------+------------+--------------
         0 |           0 |         0 |             0 |                0 |              0 |                  0 |          0 |            0
(1 row)

select * from pgstattuple('test'::regclass);
 table_len | tuple_count | tuple_len | tuple_percent | dead_tuple_count | dead_tuple_len | dead_tuple_percent | free_space | free_percent 
-----------+-------------+-----------+---------------+------------------+----------------+--------------------+------------+--------------
         0 |           0 |         0 |             0 |                0 |              0 |                  0 |          0 |            0
(1 row)

select * from pgstatindex('test_pkey');
 version | tree_level | index_size | root_block_no | internal_pages | leaf_pages | empty_pages | deleted_pages | avg_leaf_density | leaf_fragmentation 
---------+------------+------------+---------------+----------------+------------+-------------+---------------+------------------+--------------------
       2 |          0 |          0 |             0 |              0 |          0 |           0 |             0 |              NaN |                NaN
(1 row)

select pg_relpages('test');
 pg_relpages 
-------------
           0
(1 row)

select pg_relpages('test_pkey');
 pg_relpages 
-------------
           1
(1 row)