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bench | ||
data | ||
expected | ||
sql | ||
_int_bool.c | ||
_int_gin.c | ||
_int_gist.c | ||
_int_op.c | ||
_int_tool.c | ||
_int.h | ||
_int.sql.in | ||
_intbig_gist.c | ||
Makefile | ||
README.intarray | ||
uninstall__int.sql |
This is an implementation of RD-tree data structure using GiST interface of PostgreSQL. It has built-in lossy compression. Current implementation provides index support for one-dimensional array of int4's - gist__int_ops, suitable for small and medium size of arrays (used on default), and gist__intbig_ops for indexing large arrays (we use superimposed signature with length of 4096 bits to represent sets). 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. Andrey Oktyabrski did a great work on adding new functions and operations. FUNCTIONS: int icount(int[]) - the number of elements in intarray test=# select icount('{1,2,3}'::int[]); icount -------- 3 (1 row) int[] sort(int[], 'asc' | 'desc') - sort intarray test=# select sort('{1,2,3}'::int[],'desc'); sort --------- {3,2,1} (1 row) int[] sort(int[]) - sort in ascending order int[] sort_asc(int[]),sort_desc(int[]) - shortcuts for sort int[] uniq(int[]) - returns unique elements test=# select uniq(sort('{1,2,3,2,1}'::int[])); uniq --------- {1,2,3} (1 row) int idx(int[], int item) - returns index of first intarray matching element to item, or '0' if matching failed. test=# select idx('{1,2,3,2,1}'::int[],2); idx ----- 2 (1 row) int[] subarray(int[],int START [, int LEN]) - returns part of intarray starting from element number START (from 1) and length LEN. test=# select subarray('{1,2,3,2,1}'::int[],2,3); subarray ---------- {2,3,2} (1 row) int[] intset(int4) - casting int4 to int[] test=# select intset(1); intset -------- {1} (1 row) OPERATIONS: int[] && int[] - overlap - returns TRUE if arrays have at least one common element int[] @> int[] - contains - returns TRUE if left array contains right array int[] <@ int[] - contained - returns TRUE if left array is contained in right array # int[] - returns the number of elements in array int[] + int - push element to array ( add to end of array) int[] + int[] - merge of arrays (right array added to the end of left one) int[] - int - remove entries matched by right argument from array int[] - int[] - remove right array from left int[] | int - returns intarray - union of arguments int[] | int[] - returns intarray as a union of two arrays int[] & int[] - returns intersection of arrays int[] @@ query_int - returns TRUE if array satisfies query (like '1&(2|3)') query_int ~~ int[] - returns TRUE if array satisfies query (commutator of @@) (Before PostgreSQL 8.2, the containment operators @> and <@ were respectively called @ and ~. These names are still available, but are deprecated and will eventually be retired. Notice that the old names are reversed from the convention formerly followed by the core geometric datatypes!) CHANGES: August 6, 2002 1. Reworked patch from Andrey Oktyabrski (ano@spider.ru) with functions: icount, sort, sort_asc, uniq, idx, subarray operations: #, +, -, |, & October 1, 2001 1. Change search method in array to binary September 28, 2001 1. gist__int_ops now is without lossy 2. add sort entry in picksplit September 21, 2001 1. Added support for boolean query (indexable operator @@, looks like a @@ '1|(2&3)', perfomance is better in any case ) 2. Done some small optimizations March 19, 2001 1. Added support for toastable keys 2. Improved split algorithm for intbig (selection speedup is about 30%) 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 gist__int_ops); -- 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 -c -s 1,2 -v b)test with RD-Tree ./bench.pl -d TEST -c -s 1,2 -v -r BENCHMARKS: Size of table <message>: 200000 Size of table <message_section_map>: 269133 Distribution of messages by sections: section 0: 74377 messages section 1: 16284 messages section 50: 1229 messages section 99: 683 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| 0.625| 0.101| -| -| +----------+-------+-------+--------+-------+ | 99| 0.018| 0.017| -| -| +----------+-------+-------+--------+-------+ | 1,2| 0.766| 0.133| 0.628| 0.045| +----------+-------+-------+--------+-------+ | 1,2,50,65| 0.794| 0.141| 0.030| 0.006| +----------+-------+-------+--------+-------+