+++ /dev/null
-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 works was done by Teodor Sigaev (teodor@stack.net) and Oleg Bartunov
-(oleg@sai.msu.su).
-
-INSTALLATION:
-
- gmake
- gmake install
- -- load functions
- psql <database> < _int.sql
-
-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;
-
-TEST:
-
- subdirectory test contains test suite.
- cd ./test
- 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|
-+----------+-------+-------+--------+-------+