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Restructure pg_opclass, pg_amop, and pg_amproc per previous discussions in
pgsql-hackers. pg_opclass now has a row for each opclass supported by each index AM, not a row for each opclass name. This allows pg_opclass to show directly whether an AM supports an opclass, and furthermore makes it possible to store additional information about an opclass that might be AM-dependent. pg_opclass and pg_amop now store "lossy" and "haskeytype" information that we previously expected the user to remember to provide in CREATE INDEX commands. Lossiness is no longer an index-level property, but is associated with the use of a particular operator in a particular index opclass. Along the way, IndexSupportInitialize now uses the syscaches to retrieve pg_amop and pg_amproc entries. I find this reduces backend launch time by about ten percent, at the cost of a couple more special cases in catcache.c's IndexScanOK. Initial work by Oleg Bartunov and Teodor Sigaev, further hacking by Tom Lane. initdb forced.
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@ -1,10 +1,10 @@
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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 provides index
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support for one-dimensional array of int4's - gist__int_ops, suitable for
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small and medium size of arrays (used on default), and gist__intbig_ops for
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indexing large arrays (we use superimposed signature with length of 4096
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bits to represent sets).
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of PostgreSQL. It has built-in lossy compression.
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Current implementation provides index support for one-dimensional array of
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int4's - gist__int_ops, suitable for small and medium size of arrays (used on
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default), and gist__intbig_ops for indexing large arrays (we use superimposed
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signature with length of 4096 bits to represent sets).
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All work was done by Teodor Sigaev (teodor@stack.net) and Oleg Bartunov
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(oleg@sai.msu.su). See http://www.sai.msu.su/~megera/postgres/gist
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@ -35,7 +35,7 @@ EXAMPLE USAGE:
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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 gist__int_ops) with ( islossy );
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CREATE INDEX message_rdtree_idx on message using gist ( sections gist__int_ops);
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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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