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Diffstat (limited to 'contrib/intarray/README.intarray')
| -rw-r--r-- | contrib/intarray/README.intarray | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/contrib/intarray/README.intarray b/contrib/intarray/README.intarray index 2829a74855a..dc7cc9a88d2 100644 --- a/contrib/intarray/README.intarray +++ b/contrib/intarray/README.intarray @@ -1,7 +1,11 @@ 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. +in index creation - with (islossy). 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. @@ -25,7 +29,7 @@ EXAMPLE USAGE: -- 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 ); +CREATE INDEX message_rdtree_idx on message using gist ( sections gist__int_ops) with ( islossy ); -- select some messages with section in 1 OR 2 - OVERLAP operator select message.mid from message where message.sections && '{1,2}'; |