Re: Fwd: Re: [GENERAL] Howto change column leng

> -----Original Message-----
> From: Jean-Michel POURE [mailto:jm.poure@freesurf.fr]
> Sent: 07 November 2001 14:30
> To: pgadmin-hackers@postgresql.org
> Subject: [pgadmin-hackers] Fwd: Re: [GENERAL] Howto change
> column length
>
>
> Hello all,
>
> This is a copy from Admin explaining how to change variable lenght:
>
> >If you're willing to do a little magic to the system tables (and you
> >have a recent backup :) ).  You can change the atttypmod of
> the column
> >in question from 14 to 24.  This really only works on
> variable length
> >items and only to expand them, but...
> >
> >You pretty much need to do a sequence like:
> >select oid, relname from pg_class where
> relname='<tablename>'; update
> >pg_attribute set atttypmod=24 where attrelid=<oid from previous>
> >  and attname='<attributename>'
> >in a superuser account.

Though technically correct, that sounds like a recipe for disaster! Of
course, the atttypmod doesn't always relate directly to the length of the
column, and even when it does, it's usually length+4

Regards, Dave.