From: George Weaver <gweaver@shaw.ca>
To: Kenneth Gonsalves <lawgon@thenilgiris.com>
To: Richard Huxton <dev@archonet.com>
Cc: weberp@paradise.net.nz
Cc: pgsql-sql@postgresql.org
Subject: Re: Query performance problem
Date: Fri, 18 Mar 2005 07:29:54 -0600
Message-ID: <002101c52bbe$94689670$6400a8c0@Dell4500> (raw)
References: <200503172120.20676.weberp@paradise.net.nz>
<200503171801.19412.lawgon@thenilgiris.com>
<42398EB9.2050707@archonet.com>
<200503181049.47566.lawgon@thenilgiris.com>
Only specifying a default value does not prevent a NULL from being entered
either through accident or ignorance:
jan28-05=# create table test (foo text, foo1 int4 default(0));
CREATE TABLE
jan28-05=# insert into test values('a',1);
INSERT 98685 1
jan28-05=# insert into test values('b',4);
INSERT 98686 1
jan28-05=# insert into test values('c',NULL);
INSERT 98687 1
jan28-05=# insert into test values('d');
INSERT 98688 1
jan28-05=# select * from test;
foo | foo1
-----+------
a | 1
b | 4
c |
d | 0
(4 rows)
George
----- Original Message -----
From: "Kenneth Gonsalves" <lawgon@thenilgiris.com>
To: "Richard Huxton" <dev@archonet.com>
Cc: <weberp@paradise.net.nz>; <pgsql-sql@postgresql.org>
Sent: Thursday, March 17, 2005 11:19 PM
Subject: Re: [SQL] Query performance problem
On Thursday 17 Mar 2005 7:35 pm, Richard Huxton wrote:
> Not necessarily. NOT NULL here helps to ensure you can add values
> together without the risk of a null result. There are plenty of
> "amount" columns that should be not-null (total spent, total
> ordered etc).
that makes sense - but is it necessary to have a not null constraint
when there is a default value?
--
regards
kg
http://www.livejournal.com/users/lawgon
tally ho! http://avsap.sourceforge.net
ಇಂಡ್ಲಿನಕ್ಸ வாழ்க!
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To: pgsql-sql@postgresql.org
Cc: gweaver@shaw.ca, lawgon@thenilgiris.com, dev@archonet.com, weberp@paradise.net.nz
Subject: Re: Query performance problem
In-Reply-To: <002101c52bbe$94689670$6400a8c0@Dell4500>
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