Re: [HACKERS] What about LIMIT in SELECT ?

> Right. As I remember, your solution does basically the same
> as my one. It does not change the optimizers decision about
> the index or if an index at all is used. So I assume they
> hook into the same position where depending on the order by
> clause the sort node is added. And that is at the very end of
> the optimizer.
>
> What you describe above requires changes in upper levels of
> optimization. Doing that is far away from my knowledge about
> the optimizer. And some of your earlier statements let me
> think you aren't familiar enough with it too. We need at
> least help from others to do it well.
>
> I don't want to dive that deep into the optimizer. There was
> a far too long time where the rule system was broken and got
> out of sync with the parser/optimizer capabilities. I fixed
> many things in it for 6.4. My first priority now is, not to
> let such a situation come up again.

I agree. Another good thing is that the LIMIT thing will not require a
dump/reload, so it is a good candidate for a minor release.

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