On Tue, 2006-05-23 at 13:17 -0400, Tom Lane wrote:
> Simon Riggs <simon@2ndquadrant.com> writes:
> > - ADD/DROP are opposites; you can use the other one to undo an action
> > taken in haste, error etc
>
> It's not going to be that easy. What exactly will happen to the child
> table's attislocal/attinhcount settings, and why, during ADD or DROP?
Never is round here ;-)
attislocal: If you set this to False, you wouldn't be able to set it
back again. If you leave it as it is, you'd never be able to recursively
drop a column. If you change it, you'll never be able to stop someone
from dropping a previously defined local column.
Proposal:
1. attislocal is not touched.
That means if you want to create a new partition you do this:
CREATE TABLE newChild () INHERITS (template);
... do some processing ...
ALTER TABLE newChild ADD INHERITS parent;
or this:
CREATE TABLE newChild () INHERITS (parent);
ALTER TABLE newChild DROP INHERITS parent;
... do some processing ...
ALTER TABLE newChild ADD INHERITS parent;
Neither of which I like.
2. attislocal is always set False when an appropriate ADD INHERITS is
actioned. Not ever set back again.
attinhcount changes as appropriate - up for ADDs and down for DROPs.
-- Simon Riggs EnterpriseDB http://www.enterprisedb.com
