Re: Increasing the length of a VARCHAR column without table rewrite

From: Lewis Kapell <lkapell(at)setonhome(dot)org>
To: Eric Comeau <ecomeau(at)signiant(dot)com>
Cc: pgsql-admin(at)postgresql(dot)org
Subject: Re: Increasing the length of a VARCHAR column without table rewrite
Date: 2009-10-23 15:22:17
Message-ID: 4AE1CA29.9070900@setonhome.org
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Eric,

Is the table in question so large that you can't afford the time it
would take to perform ALTER COLUMN TYPE?

I definitely would not go poking around in system catalogs and changing
things there. Not unless you *want* to trash your database... The fact
that 'todo' has not yet been implemented suggests that it is not a
simple matter of changing one attribute in a system catalog.

Lewis

Eric Comeau wrote:
> ALTER TABLE .... ALTER column TYPE varchar(xxx)
>
> We need to increase the length of a varchar(256) column in two of our
> largest tables preferrably to TEXT.
>
> Is there a way to do this without having to go through a complete table
> rewrite?
>
> I have googled and seen the todo on the wiki, but I'm wondering if we are
> increasing the length of a varchar column can we manually modify the system
> catalogs to increase the length?
>
> http://wiki.postgresql.org/wiki/Todo#ALTER
>
>
> Version: PG 8.1.17
>
> Thanks,
> Eric
>
>
>
>

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