Well, it's possible to create GIN indexes on arrays of built-in data types without extra efforts, because of "GIN" access method has defaul operator class. But it's not true for GiST:
SELECT am.amname AS index_method, opc.opcname AS opclass_name FROM pg_am am, pg_opclass opc WHERE opc.opcmethod = am.oid AND am.amname = 'gist' ORDER BY index_method, opclass_name; gist | box_ops gist | circle_ops gist | point_ops gist | poly_ops gist | tsquery_ops gist | tsvector_ops With hstore I don't need to care about it at all. But thank you very much to points me about indexes on arrays ! 2010/11/12 Pavel Stehule <pavel.steh...@gmail.com> > 2010/11/12 Dmitriy Igrishin <dmit...@gmail.com>: > > Hey Peter, > > > > Unfortunately, there is no indexes on arrays (only on expressions). > > there are indexes on arrays - you can use a GiST, Gin indexes. > > regards > > Pavel > > > > With hstore we can easily create GiST index for effective access. > > > > 2010/11/12 Peter Bex <peter....@xs4all.nl> > >> > >> On Fri, Nov 12, 2010 at 10:17:50AM +0300, Dmitriy Igrishin wrote: > >> > Hey Mark, > >> > > >> > Yeah, I can't imagine an entity in a real project even with more than > >> > 100 > >> > columns. Its rare case. > >> > But if you entities (rows/tuples) of some class (table) can contains > >> > variable > >> > set of columns (properties) you can look at hstore contrib module. > >> > >> What can also work extremely well is storing the data in an array. > >> If you need to access the array based on more meaningful keys you could > >> store key/index pairs in another table. > >> > >> This approach only works well if you have multiple arrays with the same > >> layout. You probably also need to build up your query dynamically if > >> you need to access variable numbers of datapoints. > >> > >> Cheers, > >> Peter > >> -- > >> http://sjamaan.ath.cx > >> -- > >> "The process of preparing programs for a digital computer > >> is especially attractive, not only because it can be economically > >> and scientifically rewarding, but also because it can be an aesthetic > >> experience much like composing poetry or music." > >> -- Donald Knuth > >> > >> -- > >> Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > >> To make changes to your subscription: > >> http://www.postgresql.org/mailpref/pgsql-general > > > > > > > > -- > > // Dmitriy. > > > > > > > -- // Dmitriy.
