Re: IN vs EXIIST

On Thu, Sep 19, 2002 at 06:36:56PM +0900, Jean-Christian Imbeault wrote:
>
> Maybe EXISTS is not always faster than IN ?

I haven't been reading this thread very carefully, but that one is
_certainly_ true.  In testing, we have had a wide variety of results
with IN versus EXISTS.  It seems to have to do with the relative size
of the two sides.  I haven't come up with a perfect rule for deciding
yet.

NOT IN/NOT EXISTS is more often a clear-cut case: NOT EXISTS is
_almost_ (but only almost) always faster.

A

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