Re: character type modification - Mailing list pgsql-admin

From Tom Lane
Subject Re: character type modification
Date
Msg-id 25915.1071648138@sss.pgh.pa.us
Whole thread Raw
In response to character type modification  (Jodi Kanter <jkanter@virginia.edu>)
List pgsql-admin
Jodi Kanter <jkanter@virginia.edu> writes:
> Can I alter a column from character varying(128) to text without having
> to create a temp table? I am running 7.3.3.

Yeah, if you're brave enough: change the column's atttypid to 'text'
(25, I think, but check it) and atttypmod to -1 in pg_attribute.
This is sufficient since the two datatypes have the same representation
--- in general you can't just hack atttypid at random, but it will
work in this case.

Highly advisable to practice this maneuver in a scratch database.

BTW, if you're running 7.3.3 and not 7.3.4 (even better 7.3.5), you are
not being brave but foolish.  7.3.3's WAL-startup-failure bug will get
you sooner or later.

            regards, tom lane

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