Szymon Guz <mabewlun@gmail.com> writes:
> W dniu 1 marca 2010 09:40 użytkownik Grzegorz Jaśkiewicz
> <gryzman@gmail.com>napisał:
>> don't use 'NOT EXISTS', as this will be damn slow. Use LEFT JOIN.
> Right, LEFT JOIN should be faster (with proper indices even much faster).
Converting NOT EXISTS into an outer join is a manual application of an
optimization that Postgres can do for itself in 8.4 and up. So the
above advice should only be correct for 8.3 or before.
regards, tom lane