Re: A qsort template - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: A qsort template
Date
Msg-id CAH2-WzmFuVN5P-LqwunMGzjfQDvCfn11g8qfh4MbGW0pvo4Deg@mail.gmail.com
Whole thread Raw
In response to Re: A qsort template  (John Naylor <john.naylor@enterprisedb.com>)
Responses Re: A qsort template
List pgsql-hackers
On Tue, Jan 18, 2022 at 6:39 PM John Naylor
<john.naylor@enterprisedb.com> wrote:
> Editorializing the null position in queries is not very common in my
> experience. Not null is interesting since it'd be trivial to pass
> constant false to the same Apply[XYZ]SortComparator() and let the
> compiler remove all those branches for us. On the other hand, those
> branches would be otherwise predicted well, so it might make little or
> no difference.

If you were going to do this, maybe you could encode NULL directly in
an abbreviated key. I think that that could be made to work if it was
limited to opclasses with abbreviated keys encoded as unsigned
integers. Just a thought.

-- 
Peter Geoghegan



pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: Adding CI to our tree
Next
From: "osumi.takamichi@fujitsu.com"
Date:
Subject: RE: Skipping logical replication transactions on subscriber side