Scott Carey <sc...@richrelevance.com> wrote:
 
> Often, the best query plans result from 'LEFT JOIN WHERE right
> side is NULL' rather than NOT EXISTS however.  I often get
> performance gains by switching NOT EXISTS queries to LEFT JOIN
> form.
 
Even in 8.4 and later?  I would think that the anti-join that Tom
added in 8.4 would always perform at least as well as the LEFT JOIN
technique you describe.
 
-Kevin

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