From: Josh Berkus <josh@agliodbs.com>
Reply-To: josh@agliodbs.com
Organization: Aglio Database Solutions
To: pgsql-performance@postgresql.org
Subject: Re: [PERFORM] Text/Varchar performance...
Date: Wed, 5 Oct 2005 12:00:48 -0700
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Cc: "Cristian Prieto" <cristian@clickdiario.com>, pgsql-general@postgresql.org
References: <20051005182803.0E6B0100E5@mail.clickdiario.com>
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Cristian,

> Hello, just a little question, It's preferable to use Text Fields or
> varchar(255) fields in a table? Are there any performance differences in
> the use of any of them?

TEXT, VARCHAR, and CHAR use the same underlying storage mechanism.   This 
means that TEXT is actually the "fastest" since it doesn't check length or 
space-pad.  However, that's unlikely to affect you unless you've millions 
of records; you should use the type which makes sense given your 
application.

For "large text fields" I always use TEXT.  BTW, in PostgreSQL VARCHAR is 
not limited to 255; I think we support up to 1GB of text or something 
preposterous.

-- 
--Josh

Josh Berkus
Aglio Database Solutions
San Francisco