BUG #4125: Strange ALTER TABLE behavior - Mailing list pgsql-bugs

From Vladimir Kanazir
Subject BUG #4125: Strange ALTER TABLE behavior
Date
Msg-id 200804231501.m3NF1OrM017187@wwwmaster.postgresql.org
Whole thread Raw
Responses Re: BUG #4125: Strange ALTER TABLE behavior  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-bugs
The following bug has been logged online:

Bug reference:      4125
Logged by:          Vladimir Kanazir
Email address:      vladimir@vlajko.com
PostgreSQL version: 8.2.6
Operating system:   Fedora 7
Description:        Strange ALTER TABLE behavior
Details:

If I execute this query:
alter table history add incoming_id bigint default 0;

the table will be locked until operation finishes (checked by executing the
select query on the same table via another connection).

But, if I do this:
alter table history add incoming_id bigint;
alter table history alter incoming_id set default 0;
update history set incoming_id=0;
the table will be locked only during alter table execution, which is very
short time.
I think that alter table with default values should work the same way.

pgsql-bugs by date:

Previous
From: "Harald Armin Massa"
Date:
Subject: Re:
Next
From: Tom Lane
Date:
Subject: Re: BUG #4125: Strange ALTER TABLE behavior