postgresql/contrib/pg_visibility/sql/pg_visibility.sql

CREATE EXTENSION pg_visibility;
CREATE EXTENSION pageinspect;

--
-- recently-dropped table
--
\set VERBOSITY sqlstate
BEGIN;
CREATE TABLE droppedtest (c int);
SELECT 'droppedtest'::regclass::oid AS oid \gset
SAVEPOINT q; DROP TABLE droppedtest; RELEASE q;
SAVEPOINT q; SELECT * FROM pg_visibility_map(:oid); ROLLBACK TO q;
-- ERROR:  could not open relation with OID 16xxx
SAVEPOINT q; SELECT 1; ROLLBACK TO q;
SAVEPOINT q; SELECT 1; ROLLBACK TO q;
SELECT pg_relation_size(:oid), pg_relation_filepath(:oid),
  has_table_privilege(:oid, 'SELECT');
SELECT * FROM pg_visibility_map(:oid);
-- ERROR:  could not open relation with OID 16xxx
ROLLBACK;
\set VERBOSITY default

--
-- check that using the module's functions with unsupported relations will fail
--

-- partitioned tables (the parent ones) don't have visibility maps
create table test_partitioned (a int) partition by list (a);
-- these should all fail
select pg_visibility('test_partitioned', 0);
select pg_visibility_map('test_partitioned');
select pg_visibility_map_summary('test_partitioned');
select pg_check_frozen('test_partitioned');
select pg_truncate_visibility_map('test_partitioned');

create table test_partition partition of test_partitioned for values in (1);
create index test_index on test_partition (a);
-- indexes do not, so these all fail
select pg_visibility('test_index', 0);
select pg_visibility_map('test_index');
select pg_visibility_map_summary('test_index');
select pg_check_frozen('test_index');
select pg_truncate_visibility_map('test_index');

create view test_view as select 1;
-- views do not have VMs, so these all fail
select pg_visibility('test_view', 0);
select pg_visibility_map('test_view');
select pg_visibility_map_summary('test_view');
select pg_check_frozen('test_view');
select pg_truncate_visibility_map('test_view');

create sequence test_sequence;
-- sequences do not have VMs, so these all fail
select pg_visibility('test_sequence', 0);
select pg_visibility_map('test_sequence');
select pg_visibility_map_summary('test_sequence');
select pg_check_frozen('test_sequence');
select pg_truncate_visibility_map('test_sequence');

create foreign data wrapper dummy;
create server dummy_server foreign data wrapper dummy;
create foreign table test_foreign_table () server dummy_server;
-- foreign tables do not have VMs, so these all fail
select pg_visibility('test_foreign_table', 0);
select pg_visibility_map('test_foreign_table');
select pg_visibility_map_summary('test_foreign_table');
select pg_check_frozen('test_foreign_table');
select pg_truncate_visibility_map('test_foreign_table');

-- check some of the allowed relkinds
create table regular_table (a int, b text);
alter table regular_table alter column b set storage external;
insert into regular_table values (1, repeat('one', 1000)), (2, repeat('two', 1000));
vacuum (disable_page_skipping) regular_table;
select count(*) > 0 from pg_visibility('regular_table');
select count(*) > 0 from pg_visibility((select reltoastrelid from pg_class where relname = 'regular_table'));
truncate regular_table;
select count(*) > 0 from pg_visibility('regular_table');
select count(*) > 0 from pg_visibility((select reltoastrelid from pg_class where relname = 'regular_table'));

create materialized view matview_visibility_test as select * from regular_table;
vacuum (disable_page_skipping) matview_visibility_test;
select count(*) > 0 from pg_visibility('matview_visibility_test');
insert into regular_table values (1), (2);
refresh materialized view matview_visibility_test;
select count(*) > 0 from pg_visibility('matview_visibility_test');

-- regular tables which are part of a partition *do* have visibility maps
insert into test_partition values (1);
vacuum (disable_page_skipping) test_partition;
select count(*) > 0 from pg_visibility('test_partition', 0);
select count(*) > 0 from pg_visibility_map('test_partition');
select count(*) > 0 from pg_visibility_map_summary('test_partition');
select * from pg_check_frozen('test_partition'); -- hopefully none
select pg_truncate_visibility_map('test_partition');

-- test the case where vacuum phase I does not need to modify the heap buffer
-- and only needs to set the VM
create temp table test_vac_unmodified_heap(a int);
insert into test_vac_unmodified_heap values (1);
vacuum (freeze) test_vac_unmodified_heap;
select pg_visibility_map_summary('test_vac_unmodified_heap');
-- the checkpoint cleans the buffer dirtied by freezing the sole tuple
checkpoint;
-- truncating the VM ensures that the next vacuum will need to set it
select pg_truncate_visibility_map('test_vac_unmodified_heap');
select pg_visibility_map_summary('test_vac_unmodified_heap');
-- though the VM is truncated, the heap page-level visibility hint,
-- PD_ALL_VISIBLE should still be set
SELECT (flags & x'0004'::int) <> 0
        FROM page_header(get_raw_page('test_vac_unmodified_heap', 0));
-- vacuum sets the VM
vacuum test_vac_unmodified_heap;
select pg_visibility_map_summary('test_vac_unmodified_heap');

-- test copy freeze
create table copyfreeze (a int, b char(1500));

-- load all rows via COPY FREEZE and ensure that all pages are set all-visible
-- and all-frozen.
begin;
truncate copyfreeze;
copy copyfreeze from stdin freeze;
1	'1'
2	'2'
3	'3'
4	'4'
5	'5'
6	'6'
\.
commit;
select * from pg_visibility_map('copyfreeze');
select * from pg_check_frozen('copyfreeze');

-- load half the rows via regular COPY and rest via COPY FREEZE. The pages
-- which are touched by regular COPY must not be set all-visible/all-frozen. On
-- the other hand, pages allocated by COPY FREEZE should be marked
-- all-frozen/all-visible.
begin;
truncate copyfreeze;
copy copyfreeze from stdin;
1	'1'
2	'2'
3	'3'
4	'4'
5	'5'
6	'6'
\.
copy copyfreeze from stdin freeze;
7	'7'
8	'8'
9	'9'
10	'10'
11	'11'
12	'12'
\.
commit;
select * from pg_visibility_map('copyfreeze');
select * from pg_check_frozen('copyfreeze');

-- Try a mix of regular COPY and COPY FREEZE.
begin;
truncate copyfreeze;
copy copyfreeze from stdin freeze;
1	'1'
2	'2'
3	'3'
4	'4'
5	'5'
\.
copy copyfreeze from stdin;
6	'6'
\.
copy copyfreeze from stdin freeze;
7	'7'
8	'8'
9	'9'
10	'10'
11	'11'
12	'12'
\.
commit;
select * from pg_visibility_map('copyfreeze');
select * from pg_check_frozen('copyfreeze');

-- cleanup
drop table test_partitioned;
drop view test_view;
drop sequence test_sequence;
drop foreign table test_foreign_table;
drop server dummy_server;
drop foreign data wrapper dummy;
drop materialized view matview_visibility_test;
drop table regular_table;
drop table copyfreeze;