From: | Bruce Momjian <bruce(at)momjian(dot)us> |
---|---|
To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Peter Geoghegan <peter(at)2ndquadrant(dot)com>, PG Hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Inlining comparators as a performance optimisation |
Date: | 2011-12-02 20:42:21 |
Message-ID: | 201112022042.pB2KgLa00888@momjian.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Robert Haas wrote:
> On Fri, Dec 2, 2011 at 2:35 PM, Bruce Momjian <bruce(at)momjian(dot)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(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ It's impossible for everything to be true. +
From | Date | Subject | |
---|---|---|---|
Next Message | Pavel Stehule | 2011-12-02 20:47:02 | Re: review: CHECK FUNCTION statement |
Previous Message | Pavel Stehule | 2011-12-02 20:33:00 | Re: review: CHECK FUNCTION statement |