Michael, > > is it possible to use an index on the expression '(table_1.field & > > table_2.field)::int > 0' ?
Not practically, no. If it's important to you for comparisons to be indexed, then stop doing bitwise stuff and normalize your tables. Bitwise fields are what is known as "non-atomic" data, and violate the First Normal Form (or is it the Second? Don't recall). Your particular problem is one of the illustrations of why they are problematic. The only times I use bitwise fields in my systems is when: a) their content is going to be processed entirely by external (middleware/ interface) code and not queries, and b) they will never themselves be a search condition. -- -Josh Berkus Aglio Database Solutions San Francisco ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
