Szymon Guz <[email protected]> writes:
> W dniu 1 marca 2010 09:40 użytkownik Grzegorz JaÅkiewicz
> <[email protected]>napisaÅ:
>> 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
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