Jörg Kiegeland <kiegeland@xxxxxx> schrieb: > Hello, > > I created a multicolumn index on the columns c_1,..,c_n . > If I do use only a true subset of these columns in a SQL query, is the > index still efficient? > Or is it better to create another multicolumn index defined on this subset? Create several indexes for each column, since 8.1 PG can use a so called Bitmap Index Scan. Read more about that: - http://www.postgresql-support.de/pgbook/node492.html (in german, i think, you can read that) - http://en.wikipedia.org/wiki/Bitmap_index Andreas -- Really, I'm not out to destroy Microsoft. That will just be a completely unintentional side effect. (Linus Torvalds) "If I was god, I would recompile penguin with --enable-fly." (unknown) Kaufbach, Saxony, Germany, Europe. N 51.05082°, E 13.56889° -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
