George Oakman <oakm...@hotmail.com> writes: > Is it all I need to do? Will PgSQL know how to index properly a Bit String > column? Should I build the index using a special method, e.g. > CREATE INDEX myBitStringCol_idx ON myTable USING gist(myBitStringCol);
No, the default will be to build a btree index which won't help these types of queries at all. You would want a GIST index if there was a built-in GIST opclass for these kinds of queries, but sadly there isn't. You could add one fairly easily but it would require C code. I think it would be a valuable addition to Postgres if you do write one. Note that something like "WHERE myBitStringCol & B'101'" might be selecting too much of your table to make an index useful anyways. If each bit is set in half the table then you're talking about selecting 3/4 of the table in which case a full table scan would be more efficient than any index. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com Ask me about EnterpriseDB's On-Demand Production Tuning -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
