Re: Transactional DDL

And this feature i.e. transactional DDL is not there in other major RDBMS
like sql server, oracle etc?

thanks
~Harpreet

On 8/15/07, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> "Harpreet Dhaliwal" <harpreet(dot)dhaliwal01(at)gmail(dot)com> writes:
> > I read a few lines about SP compilation in postgres
> >
> http://searchoracle.techtarget.com/originalContent/0,289142,sid41_gci1179016,00.html
>
> > Is this what the Transactional DDL feature of postgresql talks about ?
>
> I'd say it's one very small aspect of what's involved in that.
>
> Updates of stored procedures are a relatively trivial matter, because a
> procedure is defined by just a single catalog entry (one row in
> pg_proc). So either you see the new version or you see the old version,
> not much to talk about. The DDL updates that are really interesting
> ... at least from an implementor's standpoint ... are the ones that
> involve coordinated changes to multiple catalog entries and some
> underlying filesystem files as well. In other words, ALTER TABLE.
> There are not that many other systems that can choose to commit or roll
> back an arbitrary collection of ALTER TABLE commands.
>
> This doesn't come for free of course. What it mostly costs you in
> Postgres-land is transient disk space requirements, since we have to
> store both the "before" and "after" states until commit/rollback.
>
> regards, tom lane
>