Re: BUG #11350: ALTER SYSTEM is not DDL?

On Fri, Sep 19, 2014 at 9:49 AM, Craig Ringer <craig@2ndquadrant.com> wrote:
>
> On 09/05/2014 08:32 PM, Amit Kapila wrote:
> >
> > and Alter System affects at system level, both of these can't
> > be considered as DDL, may be a separate category.
>
> Like CREATE USER / CREATE ROLE / CREATE DATABASE ?
>
> All those are logged as DDL.

They are different from ALTER SYSTEM in terms that they create/modify
the object (here object can be any database or cluster object) property.

Can you tell me that if we want to make ALTER SYSTEM as DDL, then
why SET or CHECKPOINT commands can't be DDL?

> Sure, you could separate them, but what real world benefit would that
offer?

At some level consistency with other databases (Oracle doesn't consider
ALTER SYSTEM as DDL, it defines statements similar to what I had mentioned
upthread).
Another point is tomorrow if some one says that I want a command like
Alter System Kill Session or some thing else on similar lines, then telling
that it is DDL might not be the right definition.

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com