Re: Inlining comparators as a performance optimisation

Robert Haas wrote:
> On Fri, Dec 2, 2011 at 2:35 PM, Bruce Momjian <bruce@momjian.us> wrote:
> > Agreed. ?Doing something once and doing something in the sort loop are
> > two different overheads.
> 
> OK, so I tried to code this up.  Adding the new amproc wasn't too
> difficult (see attached).  It wasn't obvious to me how to tie it into
> the tuplesort infrastructure, though, so instead of wasting time
> guessing what a sensible approach might be I'm going to use one of my
> lifelines and poll the audience (or is that ask an expert?).
> Currently the Tuplesortstate[1] has a pointer to an array of
> ScanKeyData objects, one per column being sorted.  But now instead of
> "FmgrInfo sk_func", the tuplesort code is going to want each scankey
> to contain "SortSupportInfo(Data?) sk_sortsupport"[2], because that's
> where we get the comparison function from.   Should I just go ahead
> and add one more member to that struct, or is there some more
> appropriate way to handle this?

Is this code immediately usable anywhere else in our codebasde, and if
so, is it generic enough?

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
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