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9f984ba6d2
Commit 16fa9b2b30 introduced a faster way to build GiST indexes, by
sorting all the data. This commit adds the sortsupport functions needed
to make use of that feature for btree_gist.
Author: Andrey Borodin
Discussion: https://www.postgresql.org/message-id/2F3F7265-0D22-44DB-AD71-8554C743D943@yandex-team.ru
90 lines
1.8 KiB
Plaintext
90 lines
1.8 KiB
Plaintext
-- char check
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CREATE TABLE chartmp (a char(32));
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\copy chartmp from 'data/char.data'
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SET enable_seqscan=on;
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SELECT count(*) FROM chartmp WHERE a < '31b0'::char(32);
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count
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-------
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587
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(1 row)
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SELECT count(*) FROM chartmp WHERE a <= '31b0'::char(32);
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count
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-------
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588
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(1 row)
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SELECT count(*) FROM chartmp WHERE a = '31b0'::char(32);
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count
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-------
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1
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(1 row)
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SELECT count(*) FROM chartmp WHERE a >= '31b0'::char(32);
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count
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-------
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401
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(1 row)
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SELECT count(*) FROM chartmp WHERE a > '31b0'::char(32);
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count
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-------
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400
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(1 row)
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SET client_min_messages = DEBUG1;
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CREATE INDEX charidx ON chartmp USING GIST ( a );
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DEBUG: building index "charidx" on table "chartmp" serially
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DEBUG: using sorted GiST build
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CREATE INDEX charidx_b ON chartmp USING GIST ( a ) WITH (buffering=on);
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DEBUG: building index "charidx_b" on table "chartmp" serially
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DROP INDEX charidx_b;
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RESET client_min_messages;
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SET enable_seqscan=off;
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SELECT count(*) FROM chartmp WHERE a < '31b0'::char(32);
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count
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-------
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587
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(1 row)
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SELECT count(*) FROM chartmp WHERE a <= '31b0'::char(32);
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count
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-------
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588
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(1 row)
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SELECT count(*) FROM chartmp WHERE a = '31b0'::char(32);
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count
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-------
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1
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(1 row)
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SELECT count(*) FROM chartmp WHERE a >= '31b0'::char(32);
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count
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-------
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401
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(1 row)
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SELECT count(*) FROM chartmp WHERE a > '31b0'::char(32);
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count
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-------
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400
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(1 row)
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-- Test index-only scans
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SET enable_bitmapscan=off;
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EXPLAIN (COSTS OFF)
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SELECT * FROM chartmp WHERE a BETWEEN '31a' AND '31c';
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QUERY PLAN
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---------------------------------------------------------------
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Index Only Scan using charidx on chartmp
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Index Cond: ((a >= '31a'::bpchar) AND (a <= '31c'::bpchar))
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(2 rows)
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SELECT * FROM chartmp WHERE a BETWEEN '31a' AND '31c';
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a
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------
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31b0
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(1 row)
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