Posted by boa sema on 02/01/07 12:57

Erland Sommarskog wrote:
> boa sema (boasema@gmail.com) writes:
>
>>Way back when, and at least in version 7 IIRC, the query optimizer gave
>>up when the where clause in a statement contained more than 4 search
>>conditions.
>
>
> This is a complete misunderstanding. What you might be thinking of is
> that in SQL 6.5 and earlier version, the optimizer would only consider
> four tables at a time, so if you had a query like:
>
> SELECT ...
> FROM a, b, c, d, e
> WHERE ....
>
> the optimizer would first look at (a, b, c, d) as a group, and then
> (b, c, d, e) as a group. This mean that if the best plan was to start
> with e and then take a next, the optimizer would most likely not find
> plan.

That's what I was thinking of. It was a very, very long time ago,
impressing that you still remember the details as well as you do.

Now that you've clarified it so well, this is not an issue anymore. I
remembered incorrectly.

Thanks.
Boa

[snip]

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