Date: Thu, 20 Oct 2005 21:45:29 -0300 (ADT)
From: "Marc G. Fournier" <scrappy@postgresql.org>
To: Doug Quale <quale1@charter.net>
Cc: pgsql-general@postgresql.org
Subject: Re: [pgsql-advocacy] Oracle buys Innobase
In-Reply-To: <878xwokk4d.fsf@charter.net>
Message-ID: <20051020214518.Q1006@ganymede.hub.org>
References: 
 <CC1CF380F4D70844B01D45982E671B239E8BEC@mtxexch01.add0.masergy.com>
	<878xwokk4d.fsf@charter.net>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed

On Thu, 20 Oct 2005, Doug Quale wrote:

> "Guy Rouillier" <guyr@masergy.com> writes:
>
>> Doug Quale wrote:
>>>
>>> # select 'a'::char(8) = 'a '::char(8);
>>>  ?column?
>>> ----------
>>>  t
>>> (1 row)
>>>
>>> Trailing blanks aren't significant in fixed-length strings, so the
>>> question is whether Postgresql treats comparison of varchars right.
>>
>> This result is being misinterpreted.
>>
>> select length('a'::char(8)) ==> 1
>> select length('a '::char(8)) ==> 1
>>
>> So it isn't that the two different strings are comparing equal.  The
>> process of casting them to char(8) is trimming the blanks, so by the
>> time they become fixed length strings, they are indeed equal.
>
> Huh??? What version of PG are you using?  On 7.4.9,
>
>
> test=# select length('a'::char(8));
> length
> --------
>      8
> (1 row)
>
> test=# select length('a '::char(8));
> length
> --------
>      8
> (1 row)
>
> The truncation you describe would simply be wrong.

ams=# select length('a '::char(8));
  length
--------
       1
(1 row)

ams=# select version();
                                version
----------------------------------------------------------------------
  PostgreSQL 8.0.2 on i386-portbld-freebsd4.11, compiled by GCC 2.95.4
(1 row)

ams=#


----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email: scrappy@hub.org           Yahoo!: yscrappy              ICQ: 7615664