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