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--
-- Test GIN indexes.
--
-- There are other tests to test different GIN opclasses. This is for testing
-- GIN itself.
-- Create and populate a test table with a GIN index.
create table gin_test_tbl(i int4[]) with (autovacuum_enabled = off);
create index gin_test_idx on gin_test_tbl using gin (i)
with (fastupdate = on, gin_pending_list_limit = 4096);
insert into gin_test_tbl select array[1, 2, g] from generate_series(1, 20000) g;
insert into gin_test_tbl select array[1, 3, g] from generate_series(1, 1000) g;
select gin_clean_pending_list('gin_test_idx')>10 as many; -- flush the fastupdate buffers
many
------
t
(1 row)
insert into gin_test_tbl select array[3, 1, g] from generate_series(1, 1000) g;
vacuum gin_test_tbl; -- flush the fastupdate buffers
select gin_clean_pending_list('gin_test_idx'); -- nothing to flush
gin_clean_pending_list
------------------------
0
(1 row)
-- Test vacuuming
delete from gin_test_tbl where i @> array[2];
vacuum gin_test_tbl;
-- Disable fastupdate, and do more insertions. With fastupdate enabled, most
-- insertions (by flushing the list pages) cause page splits. Without
-- fastupdate, we get more churn in the GIN data leaf pages, and exercise the
-- recompression codepaths.
alter index gin_test_idx set (fastupdate = off);
insert into gin_test_tbl select array[1, 2, g] from generate_series(1, 1000) g;
insert into gin_test_tbl select array[1, 3, g] from generate_series(1, 1000) g;
delete from gin_test_tbl where i @> array[2];
vacuum gin_test_tbl;
-- Test for "rare && frequent" searches
explain (costs off)
select count(*) from gin_test_tbl where i @> array[1, 999];
QUERY PLAN
-------------------------------------------------------
Aggregate
-> Bitmap Heap Scan on gin_test_tbl
Recheck Cond: (i @> '{1,999}'::integer[])
-> Bitmap Index Scan on gin_test_idx
Index Cond: (i @> '{1,999}'::integer[])
(5 rows)
select count(*) from gin_test_tbl where i @> array[1, 999];
count
-------
3
(1 row)
-- Very weak test for gin_fuzzy_search_limit
set gin_fuzzy_search_limit = 1000;
explain (costs off)
select count(*) > 0 as ok from gin_test_tbl where i @> array[1];
QUERY PLAN
---------------------------------------------------
Aggregate
-> Bitmap Heap Scan on gin_test_tbl
Recheck Cond: (i @> '{1}'::integer[])
-> Bitmap Index Scan on gin_test_idx
Index Cond: (i @> '{1}'::integer[])
(5 rows)
select count(*) > 0 as ok from gin_test_tbl where i @> array[1];
ok
----
t
(1 row)
reset gin_fuzzy_search_limit;
-- Test optimization of empty queries
create temp table t_gin_test_tbl(i int4[], j int4[]);
create index on t_gin_test_tbl using gin (i, j);
insert into t_gin_test_tbl
values
(null, null),
('{}', null),
('{1}', null),
('{1,2}', null),
(null, '{}'),
(null, '{10}'),
('{1,2}', '{10}'),
('{2}', '{10}'),
('{1,3}', '{}'),
('{1,1}', '{10}');
set enable_seqscan = off;
explain (costs off)
select * from t_gin_test_tbl where array[0] <@ i;
QUERY PLAN
---------------------------------------------------
Bitmap Heap Scan on t_gin_test_tbl
Recheck Cond: ('{0}'::integer[] <@ i)
-> Bitmap Index Scan on t_gin_test_tbl_i_j_idx
Index Cond: (i @> '{0}'::integer[])
(4 rows)
select * from t_gin_test_tbl where array[0] <@ i;
i | j
---+---
(0 rows)
select * from t_gin_test_tbl where array[0] <@ i and '{}'::int4[] <@ j;
i | j
---+---
(0 rows)
explain (costs off)
select * from t_gin_test_tbl where i @> '{}';
QUERY PLAN
---------------------------------------------------
Bitmap Heap Scan on t_gin_test_tbl
Recheck Cond: (i @> '{}'::integer[])
-> Bitmap Index Scan on t_gin_test_tbl_i_j_idx
Index Cond: (i @> '{}'::integer[])
(4 rows)
select * from t_gin_test_tbl where i @> '{}';
i | j
-------+------
{} |
{1} |
{1,2} |
{1,2} | {10}
{2} | {10}
{1,3} | {}
{1,1} | {10}
(7 rows)
create function explain_query_json(query_sql text)
returns table (explain_line json)
language plpgsql as
$$
begin
set enable_seqscan = off;
set enable_bitmapscan = on;
return query execute 'EXPLAIN (ANALYZE, FORMAT json) ' || query_sql;
end;
$$;
create function execute_text_query_index(query_sql text)
returns setof text
language plpgsql
as
$$
begin
set enable_seqscan = off;
set enable_bitmapscan = on;
return query execute query_sql;
end;
$$;
create function execute_text_query_heap(query_sql text)
returns setof text
language plpgsql
as
$$
begin
set enable_seqscan = on;
set enable_bitmapscan = off;
return query execute query_sql;
end;
$$;
-- check number of rows returned by index and removed by recheck
select
query,
js->0->'Plan'->'Plans'->0->'Actual Rows' as "return by index",
js->0->'Plan'->'Rows Removed by Index Recheck' as "removed by recheck",
(res_index = res_heap) as "match"
from
(values
($$ i @> '{}' $$),
($$ j @> '{}' $$),
($$ i @> '{}' and j @> '{}' $$),
($$ i @> '{1}' $$),
($$ i @> '{1}' and j @> '{}' $$),
($$ i @> '{1}' and i @> '{}' and j @> '{}' $$),
($$ j @> '{10}' $$),
($$ j @> '{10}' and i @> '{}' $$),
($$ j @> '{10}' and j @> '{}' and i @> '{}' $$),
($$ i @> '{1}' and j @> '{10}' $$)
) q(query),
lateral explain_query_json($$select * from t_gin_test_tbl where $$ || query) js,
lateral execute_text_query_index($$select string_agg((i, j)::text, ' ') from t_gin_test_tbl where $$ || query) res_index,
lateral execute_text_query_heap($$select string_agg((i, j)::text, ' ') from t_gin_test_tbl where $$ || query) res_heap;
query | return by index | removed by recheck | match
-------------------------------------------+-----------------+--------------------+-------
i @> '{}' | 7 | 0 | t
j @> '{}' | 6 | 0 | t
i @> '{}' and j @> '{}' | 4 | 0 | t
i @> '{1}' | 5 | 0 | t
i @> '{1}' and j @> '{}' | 3 | 0 | t
i @> '{1}' and i @> '{}' and j @> '{}' | 3 | 0 | t
j @> '{10}' | 4 | 0 | t
j @> '{10}' and i @> '{}' | 3 | 0 | t
j @> '{10}' and j @> '{}' and i @> '{}' | 3 | 0 | t
i @> '{1}' and j @> '{10}' | 2 | 0 | t
(10 rows)
reset enable_seqscan;
reset enable_bitmapscan;
-- re-purpose t_gin_test_tbl to test scans involving posting trees
insert into t_gin_test_tbl select array[1, g, g/10], array[2, g, g/10]
from generate_series(1, 20000) g;
select gin_clean_pending_list('t_gin_test_tbl_i_j_idx') is not null;
?column?
----------
t
(1 row)
analyze t_gin_test_tbl;
set enable_seqscan = off;
set enable_bitmapscan = on;
explain (costs off)
select count(*) from t_gin_test_tbl where j @> array[50];
QUERY PLAN
---------------------------------------------------------
Aggregate
-> Bitmap Heap Scan on t_gin_test_tbl
Recheck Cond: (j @> '{50}'::integer[])
-> Bitmap Index Scan on t_gin_test_tbl_i_j_idx
Index Cond: (j @> '{50}'::integer[])
(5 rows)
select count(*) from t_gin_test_tbl where j @> array[50];
count
-------
11
(1 row)
explain (costs off)
select count(*) from t_gin_test_tbl where j @> array[2];
QUERY PLAN
---------------------------------------------------------
Aggregate
-> Bitmap Heap Scan on t_gin_test_tbl
Recheck Cond: (j @> '{2}'::integer[])
-> Bitmap Index Scan on t_gin_test_tbl_i_j_idx
Index Cond: (j @> '{2}'::integer[])
(5 rows)
select count(*) from t_gin_test_tbl where j @> array[2];
count
-------
20000
(1 row)
explain (costs off)
select count(*) from t_gin_test_tbl where j @> '{}'::int[];
QUERY PLAN
---------------------------------------------------------
Aggregate
-> Bitmap Heap Scan on t_gin_test_tbl
Recheck Cond: (j @> '{}'::integer[])
-> Bitmap Index Scan on t_gin_test_tbl_i_j_idx
Index Cond: (j @> '{}'::integer[])
(5 rows)
select count(*) from t_gin_test_tbl where j @> '{}'::int[];
count
-------
20006
(1 row)
reset enable_seqscan;
reset enable_bitmapscan;
drop table t_gin_test_tbl;
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