mirror of https://github.com/postgres/postgres
Bruce Momjian
25 years ago
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This is an implementation of RD-tree data structure using GiST interface |
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of PostgreSQL. It has built-in lossy compression - must be declared |
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in index creation - with (islossy). Current implementation has index support |
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for one-dimensional array of int4's. |
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All works was done by Teodor Sigaev (teodor@stack.net) and Oleg Bartunov |
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(oleg@sai.msu.su). |
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INSTALLATION: |
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gmake |
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gmake install |
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-- load functions |
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psql <database> < _int.sql |
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EXAMPLE USAGE: |
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create table message (mid int not null,sections int[]); |
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create table message_section_map (mid int not null,sid int not null); |
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-- create indices |
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CREATE unique index message_key on message ( mid ); |
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CREATE unique index message_section_map_key2 on message_section_map (sid, mid ); |
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CREATE INDEX message_rdtree_idx on message using gist ( sections ) with ( islossy ); |
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-- select some messages with section in 1 OR 2 - OVERLAP operator |
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select message.mid from message where message.sections && '{1,2}'; |
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-- select messages contains in sections 1 AND 2 - CONTAINS operator |
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select message.mid from message where message.sections @ '{1,2}'; |
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-- the same, CONTAINED operator |
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select message.mid from message where '{1,2}' ~ message.sections; |
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TEST: |
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subdirectory test contains test suite. |
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cd ./test |
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1. createdb TEST |
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2. psql TEST < ../_int.sql |
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3. ./create_test.pl | psql TEST |
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4. ./bench.pl - perl script to benchmark queries, supports OR, AND queries |
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with/without RD-Tree. Run script without arguments to |
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see availbale options. |
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a)test without RD-Tree (OR) |
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./bench.pl -d TEST -s 1,2 -v |
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b)test with RD-Tree |
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./bench.pl -d TEST -s 1,2 -v -r |
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BENCHMARKS: |
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Size of table <message>: 200000 |
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Size of table <message_section_map>: 268538 |
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Distribution of messages by sections: |
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section 0: 73899 messages |
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section 1: 16298 messages |
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section 50: 1241 messages |
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section 99: 705 messages |
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old - without RD-Tree support, |
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new - with RD-Tree |
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+----------+---------------+----------------+ |
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|Search set|OR, time in sec|AND, time in sec| |
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| +-------+-------+--------+-------+ |
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| | old | new | old | new | |
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+----------+-------+-------+--------+-------+ |
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| 1| 1.427| 0.215| -| -| |
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+----------+-------+-------+--------+-------+ |
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| 99| 1.029| 0.018| -| -| |
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+----------+-------+-------+--------+-------+ |
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| 1,2| 1.829| 0.334| 5.654| 0.042| |
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+----------+-------+-------+--------+-------+ |
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| 1,2,50,60| 2.057| 0.359| 5.044| 0.007| |
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+----------+-------+-------+--------+-------+ |
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