David Jarvis <thangalin@xxxxxxxxx> writes: > I was thinking that I could add three more columns to the measurement table: > year_taken, month_taken, day_taken > Then index those. That should allow me to avoid extracting years, months, > and days from the *m.taken* date column. You could, but I don't think there's any advantage to that versus putting indexes on extract(day from taken) etc. The extra fields eat more space in the table proper, and the functional index isn't really any more expensive than a plain index. Not to mention that you can have bugs with changing the date and forgetting to update the derived columns, etc etc. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
