Re: [HACKERS] memory layouts for binary search in nbtree - Mailing list pgsql-hackers

From Andres Freund
Subject Re: [HACKERS] memory layouts for binary search in nbtree
Date
Msg-id 20170627180536.j2frg4fo4fxv7ori@alap3.anarazel.de
Whole thread Raw
In response to Re: memory layouts for binary search in nbtree  (Peter Geoghegan <pg@heroku.com>)
Responses Re: [HACKERS] memory layouts for binary search in nbtree  (Peter Geoghegan <pg@bowt.ie>)
List pgsql-hackers
On 2016-05-19 19:38:02 -0700, Peter Geoghegan wrote:
> On Wed, May 18, 2016 at 6:25 AM, Andres Freund <andres@anarazel.de> wrote:
> > currently we IIRC use linearly sorted datums for the search in
> > individual btree nodes.  Not surprisingly that's often one of the
> > dominant entries in profiles. We could probably improve upon that by
> > using an order more optimized for efficient binary search.
> 
> Did you ever try running a pgbench SELECT benchmark, having modified
> things such that all PKs are on columns that are not of type
> int4/int8, but rather are of type numeric? It's an interesting
> experiment, that I've been meaning to re-run on a big box.

> Obviously this will be slower than an equivalent plain pgbench SELECT,
> but the difference may be smaller than you expect.

I'm not sure what that has to do with the topic?

- Andres



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