Skip site navigation (1) Skip section navigation (2)

Re: 8.x index insert performance

From: "Merlin Moncure" <merlin(dot)moncure(at)rcsonline(dot)com>
To: "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: <pgsql-performance(at)postgresql(dot)org>,"Kelly Burkhart" <kelly(at)tradebotsystems(dot)com>
Subject: Re: 8.x index insert performance
Date: 2005-10-31 21:01:34
Message-ID: 6EE64EF3AB31D5448D0007DD34EEB3417DD731@Herge.rcsinc.local (view raw or flat)
Thread:
Lists: pgsql-performance
> mark(at)mark(dot)mielke(dot)cc writes:
> > I've been trying to figure out whether null values are indexed or
not
> from
> > the documentation. I was under the impression, that null values are
not
> > stored in the index.
> 
> You're mistaken, at least with regard to btree indexes.

hmm. I tried several different ways to filter/extract null values from
an indexed key and got a seq scan every time.  The only way I could
query for/against null values was to convert to bool via function.

However I did a partial exclusion on a 1% non null value really big
table and index size dropped as expected.

Merlin

Responses

pgsql-performance by date

Next:From: Scott MarloweDate: 2005-10-31 21:03:53
Subject: Re: 8.x index insert performance
Previous:From: Kelly BurkhartDate: 2005-10-31 20:59:51
Subject: Re: 8.x index insert performance

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group