How are null's stored? - Mailing list pgsql-performance

From Jim C. Nasby
Subject How are null's stored?
Date
Msg-id 20030512190156.GA40542@flake.decibel.org
Whole thread Raw
Responses Re: How are null's stored?
Re: How are null's stored? -- Some numbers
List pgsql-performance
I have a 40M row table I need to import data into, then use to create a
bunch of more normalized tables. Right now all fields are varchar, but
I'm going to change this so that fields that are less than a certain
size are just char. Question is, how much impact is there from char
being nullable vs. not nullable? src/include/access/htup.h indicates
that nulls are stored in a bitmap, so I'd suspect that I should see a
decent space savings from not having to include length information all
the time... (most of these small fields are always the same size no
matter what...)
--
Jim C. Nasby (aka Decibel!)                    jim@nasby.net
Member: Triangle Fraternity, Sports Car Club of America
Give your computer some brain candy! www.distributed.net Team #1828

Windows: "Where do you want to go today?"
Linux: "Where do you want to go tomorrow?"
FreeBSD: "Are you guys coming, or what?"


pgsql-performance by date:

Previous
From: Steve Crawford
Date:
Subject: Re: [GENERAL] realtime data inserts
Next
From: Josh Berkus
Date:
Subject: Re: How are null's stored?