Re: Table rewrites vs. pending AFTER triggers

On Jan 3, 2008 3:53 PM, Martijn van Oosterhout <kleptog(at)svana(dot)org> wrote:

> On Thu, Jan 03, 2008 at 01:08:47PM +0530, Gokulakannan Somasundaram wrote:
> > Can you please explain, any specific use-case where DDLs are necessary
> > within a transaction?
>
> I don't think they are ever necessary, they're just very very nice. For
> example:
>
> - You want a new column to appear populated on a table atomically. You
> do a BEGIN; add column; update set column=foo; add foreign key; COMMIT
> - Installation of external modules can be done atomically, so you don't
> end up with half installed contrib modules.
> - Principle of Least Surprise. Automatic commit for any reason seems
> wrong.
> - Temporarily disabling triggers/indexes/constraints, if the system
> aborts/crashes, the triggers are reinstated automatically.
> - Just general niceity of being able to test schema changes without
> immediatly changing the system.
>
> There are many more...

Thanks.. it looks like a good feature...

Gokul.