Mark Lewis <mark.lewis@xxxxxxxx> writes: > What you probably want to do is tell PG that you're looking for a > literal underscore and not for any matching character by escaping the > underscore, that will allow it to do a much quicker index scan. The other half of the problem is that the planner is drastically misestimating the number of matching rows --- it thinks only one when there are really about a thousand, and this leads it to use a nestloop that will be very inefficient with so many rows. Try increasing the statistics target for that column. Also, if this is a pre-8.2 PG release, consider upgrading; I believe we improved the LIKE estimator in 8.2. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
