mirror of
https://github.com/postgres/postgres.git
synced 2025-11-03 09:13:20 +03:00
e09b48316c
inet, cidr, and timetz indexes still cannot support index-only scans, because they don't store the original unmodified value in the index, but a derived approximate value.
92 lines
1.7 KiB
Plaintext
92 lines
1.7 KiB
Plaintext
-- date check
|
|
CREATE TABLE datetmp (a date);
|
|
\copy datetmp from 'data/date.data'
|
|
SET enable_seqscan=on;
|
|
SELECT count(*) FROM datetmp WHERE a < '2001-02-13';
|
|
count
|
|
-------
|
|
230
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM datetmp WHERE a <= '2001-02-13';
|
|
count
|
|
-------
|
|
231
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM datetmp WHERE a = '2001-02-13';
|
|
count
|
|
-------
|
|
1
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM datetmp WHERE a >= '2001-02-13';
|
|
count
|
|
-------
|
|
314
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM datetmp WHERE a > '2001-02-13';
|
|
count
|
|
-------
|
|
313
|
|
(1 row)
|
|
|
|
SELECT a, a <-> '2001-02-13' FROM datetmp ORDER BY a <-> '2001-02-13' LIMIT 3;
|
|
a | ?column?
|
|
------------+----------
|
|
02-13-2001 | 0
|
|
02-11-2001 | 2
|
|
03-24-2001 | 39
|
|
(3 rows)
|
|
|
|
CREATE INDEX dateidx ON datetmp USING gist ( a );
|
|
SET enable_seqscan=off;
|
|
SELECT count(*) FROM datetmp WHERE a < '2001-02-13'::date;
|
|
count
|
|
-------
|
|
230
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM datetmp WHERE a <= '2001-02-13'::date;
|
|
count
|
|
-------
|
|
231
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM datetmp WHERE a = '2001-02-13'::date;
|
|
count
|
|
-------
|
|
1
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM datetmp WHERE a >= '2001-02-13'::date;
|
|
count
|
|
-------
|
|
314
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM datetmp WHERE a > '2001-02-13'::date;
|
|
count
|
|
-------
|
|
313
|
|
(1 row)
|
|
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT a, a <-> '2001-02-13' FROM datetmp ORDER BY a <-> '2001-02-13' LIMIT 3;
|
|
QUERY PLAN
|
|
------------------------------------------------
|
|
Limit
|
|
-> Index Only Scan using dateidx on datetmp
|
|
Order By: (a <-> '02-13-2001'::date)
|
|
(3 rows)
|
|
|
|
SELECT a, a <-> '2001-02-13' FROM datetmp ORDER BY a <-> '2001-02-13' LIMIT 3;
|
|
a | ?column?
|
|
------------+----------
|
|
02-13-2001 | 0
|
|
02-11-2001 | 2
|
|
03-24-2001 | 39
|
|
(3 rows)
|
|
|