Re: How to handle 'not a number' in postgresql - Mailing list pgsql-general

From Michael Glaesemann
Subject Re: How to handle 'not a number' in postgresql
Date
Msg-id 6A006968-01F4-4928-AB79-F8EA22BB6F73@myyearbook.com
Whole thread Raw
In response to Re: How to handle 'not a number' in postgresql  (Rich Shepard <rshepard@appl-ecosys.com>)
List pgsql-general
On Jan 4, 2008, at 10:00 AM, Rich Shepard wrote:

> Maybe we have a difference in semantics that is dependent upon
> the application.

The distinction can be important, as SQL has only partially
implemented 3-valued logic (TRUE/FALSE/UNKNOWN) and treats NULL in
sometimes unexpected ways. NaN could be a useful value to distinguish
between truly unknown quantities (say, that particular machine was not
taking measurements during a particular test) and those where you've
received a value from a machine and it's NaN. But I agree, it does
depend on the application.

Michael Glaesemann
michael.glaesemann@myyearbook.com




pgsql-general by date:

Previous
From: Rich Shepard
Date:
Subject: Re: How to handle 'not a number' in postgresql
Next
From: "Joshua D. Drake"
Date:
Subject: Re: TCL