Re: [PATCHES] [SQL] 16 parameter limit

Tom Lane wrote:
> Peter Eisentraut <peter_e(at)gmx(dot)net> writes:
> > How about this: We store the first 16 parameters in some fixed array for
> > fast access like now, and when you have more than 16 then 17 and beyond
> > get stored in some variable array in pg_proc.
>
> <<itch>> What's this going to cost us in the function lookup code paths?
>
> If we can do it with little or no performance cost (at least for the
> "normal case" of fewer-than-N parameters) then I'm all ears.

OK, I have an idea. Tom, didn't you just add code that allows the cache
to return multiple rows for a lookup? I think you did it for schemas.

What if we lookup on the first 16 params, then look at every matching
hit if there are more than 16 params supplied? Another idea would be to
hash the function arg types and look that up rather than looking for
exact matches of oidvector.

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