Postgres partial index on IS NULL not working
0
CREATE TABLE tickets (
id bigserial primary key,
state character varying,
closed timestamp
);
CREATE INDEX "state_index" ON "tickets" ("state")
WHERE ((state)::text = 'open'::text));
A query with a condition on state performs well using an index scan as expected:
explain analyze select * from tickets where state = 'open';
Index Scan using state_index on tickets (cost=0.29..16093.57 rows=36599 width=212) (actual time=0.025..22.875 rows=37346 loops=1)
Planning time: 0.212 ms
Execution time: 25.697 ms
I am trying to achieve the same or better performance for the query with the condition closed IS NULL:
select * from tickets where closed IS NULL;
However, my partial indexes does not result in a single index scan like the first query.
CREATE INDEX "closed_index" ON "tickets" ("closed") WHERE (closed IS NULL)
explain analyze select * from tickets where closed IS NULL;
Bitmap Heap Scan on tickets (cost=604.22..38697.91 rows=36559 width=212) (actual time=12.879..48.780 rows=37348 loops=1)
Recheck Cond: (closed IS NULL)
Heap Blocks: exact=14757
-> Bitmap Index Scan on closed_index (cost=0.00..595.09 rows=36559 width=0) (actual time=7.585..7.585 rows=37348 loops=1)
Planning time: 4.831 ms
Execution time: 52.068 ms
postgresql index postgresql-performance
asked 5 mins ago
GeekJockGeekJock
1134
add a comment |
0
CREATE TABLE tickets (
id bigserial primary key,
state character varying,
closed timestamp
);
CREATE INDEX "state_index" ON "tickets" ("state")
WHERE ((state)::text = 'open'::text));
A query with a condition on state performs well using an index scan as expected:
explain analyze select * from tickets where state = 'open';
Index Scan using state_index on tickets (cost=0.29..16093.57 rows=36599 width=212) (actual time=0.025..22.875 rows=37346 loops=1)
Planning time: 0.212 ms
Execution time: 25.697 ms
I am trying to achieve the same or better performance for the query with the condition closed IS NULL:
select * from tickets where closed IS NULL;
However, my partial indexes does not result in a single index scan like the first query.
CREATE INDEX "closed_index" ON "tickets" ("closed") WHERE (closed IS NULL)
explain analyze select * from tickets where closed IS NULL;
Bitmap Heap Scan on tickets (cost=604.22..38697.91 rows=36559 width=212) (actual time=12.879..48.780 rows=37348 loops=1)
Recheck Cond: (closed IS NULL)
Heap Blocks: exact=14757
-> Bitmap Index Scan on closed_index (cost=0.00..595.09 rows=36559 width=0) (actual time=7.585..7.585 rows=37348 loops=1)
Planning time: 4.831 ms
Execution time: 52.068 ms
postgresql index postgresql-performance
asked 5 mins ago
GeekJockGeekJock
1134
add a comment |
0
0
0
CREATE TABLE tickets (
id bigserial primary key,
state character varying,
closed timestamp
);
CREATE INDEX "state_index" ON "tickets" ("state")
WHERE ((state)::text = 'open'::text));
A query with a condition on state performs well using an index scan as expected:
explain analyze select * from tickets where state = 'open';
Index Scan using state_index on tickets (cost=0.29..16093.57 rows=36599 width=212) (actual time=0.025..22.875 rows=37346 loops=1)
Planning time: 0.212 ms
Execution time: 25.697 ms
I am trying to achieve the same or better performance for the query with the condition closed IS NULL:
select * from tickets where closed IS NULL;
However, my partial indexes does not result in a single index scan like the first query.
CREATE INDEX "closed_index" ON "tickets" ("closed") WHERE (closed IS NULL)
explain analyze select * from tickets where closed IS NULL;
Bitmap Heap Scan on tickets (cost=604.22..38697.91 rows=36559 width=212) (actual time=12.879..48.780 rows=37348 loops=1)
Recheck Cond: (closed IS NULL)
Heap Blocks: exact=14757
-> Bitmap Index Scan on closed_index (cost=0.00..595.09 rows=36559 width=0) (actual time=7.585..7.585 rows=37348 loops=1)
Planning time: 4.831 ms
Execution time: 52.068 ms
postgresql index postgresql-performance
asked 5 mins ago
GeekJockGeekJock
1134
CREATE TABLE tickets (
id bigserial primary key,
state character varying,
closed timestamp
);
CREATE INDEX "state_index" ON "tickets" ("state")
WHERE ((state)::text = 'open'::text));
A query with a condition on state performs well using an index scan as expected:
explain analyze select * from tickets where state = 'open';
Index Scan using state_index on tickets (cost=0.29..16093.57 rows=36599 width=212) (actual time=0.025..22.875 rows=37346 loops=1)
Planning time: 0.212 ms
Execution time: 25.697 ms
I am trying to achieve the same or better performance for the query with the condition closed IS NULL:
select * from tickets where closed IS NULL;
However, my partial indexes does not result in a single index scan like the first query.
CREATE INDEX "closed_index" ON "tickets" ("closed") WHERE (closed IS NULL)
explain analyze select * from tickets where closed IS NULL;
Bitmap Heap Scan on tickets (cost=604.22..38697.91 rows=36559 width=212) (actual time=12.879..48.780 rows=37348 loops=1)
Recheck Cond: (closed IS NULL)
Heap Blocks: exact=14757
-> Bitmap Index Scan on closed_index (cost=0.00..595.09 rows=36559 width=0) (actual time=7.585..7.585 rows=37348 loops=1)
Planning time: 4.831 ms
Execution time: 52.068 ms
postgresql index postgresql-performance
postgresql index postgresql-performance
asked 5 mins ago
GeekJockGeekJock
1134
asked 5 mins ago
GeekJockGeekJock
1134
asked 5 mins ago
GeekJockGeekJock
1134
asked 5 mins ago
GeekJockGeekJock
1134
asked 5 mins ago
GeekJockGeekJock
1134
1134
add a comment |
add a comment |
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