On Thu, Feb 10, 2011 at 9:57 AM, Josh <slus...@gmail.com> wrote: > Hi > > I'm trying to do a DELETE FROM on my large table (about 800 million > rows) based on the contents of another, moderately large table (about > 110 million rows). The command I'm using is: > > DELETE FROM records WHERE id NOT IN (SELECT id FROM unique_records); > > This process ran for about two weeks before I decided to stop it -- it > was dragging down the DB server. I can understand long-running > processes, but two weeks seems a bit much even for a big table. > > Is this the best way to approach the problem? Is there a better way? >
You need delete from records r where not exists (select 1 from unique_records ur where ur.id = r.id);
