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Bloom index contrib module

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Module provides new access method. It is actually a simple Bloom filter
implemented as pgsql's index. It could give some benefits on search
with large number of columns.

Module is a single way to test generic WAL interface committed earlier.

Author: Teodor Sigaev, Alexander Korotkov
Reviewers: Aleksander Alekseev, Michael Paquier, Jim Nasby
This commit is contained in:
Teodor Sigaev
2016-04-01 16:42:24 +03:00
parent 4e56e5a6de
commit 9ee014fc89
18 changed files with 2126 additions and 0 deletions
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47
contrib/bloom/sql/bloom.sql Normal file
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CREATE EXTENSION bloom;
CREATE TABLE tst (
i int4,
t text
);
INSERT INTO tst SELECT i%10, substr(md5(i::text), 1, 1) FROM generate_series(1,100000) i;
CREATE INDEX bloomidx ON tst USING bloom (i, t) WITH (col1 = 3);
SET enable_seqscan=on;
SET enable_bitmapscan=off;
SET enable_indexscan=off;
SELECT count(*) FROM tst WHERE i = 7;
SELECT count(*) FROM tst WHERE t = '5';
SELECT count(*) FROM tst WHERE i = 7 AND t = '5';
SET enable_seqscan=off;
SET enable_bitmapscan=on;
SET enable_indexscan=on;
EXPLAIN (COSTS OFF) SELECT count(*) FROM tst WHERE i = 7;
EXPLAIN (COSTS OFF) SELECT count(*) FROM tst WHERE t = '5';
EXPLAIN (COSTS OFF) SELECT count(*) FROM tst WHERE i = 7 AND t = '5';
SELECT count(*) FROM tst WHERE i = 7;
SELECT count(*) FROM tst WHERE t = '5';
SELECT count(*) FROM tst WHERE i = 7 AND t = '5';
DELETE FROM tst;
INSERT INTO tst SELECT i%10, substr(md5(i::text), 1, 1) FROM generate_series(1,100000) i;
VACUUM ANALYZE tst;
SELECT count(*) FROM tst WHERE i = 7;
SELECT count(*) FROM tst WHERE t = '5';
SELECT count(*) FROM tst WHERE i = 7 AND t = '5';
VACUUM FULL tst;
SELECT count(*) FROM tst WHERE i = 7;
SELECT count(*) FROM tst WHERE t = '5';
SELECT count(*) FROM tst WHERE i = 7 AND t = '5';
RESET enable_seqscan;
RESET enable_bitmapscan;
RESET enable_indexscan;