One last question, using the "weather report" example, is it going to improve performance for the DISTINCT ON query to add an index to the location and time columns?
"Travis Whitton" <tinymountain@gmail.com> writes: > Given the following test table, I want to grab only the newest record and > disregard any older duplicates based on name. Is this the most efficient way > to do it?
No, it's gonna be pretty awful. The best way I know of involves DISTINCT ON (see the "weather reports" example in the SELECT reference page). Unfortunately that's a Postgres-only construct. If you want something portable then you'll need something messy with subqueries...
