Re: Identifying user-created objects

On Thu, 6 Feb 2020 at 17:18, Masahiko Sawada
<masahiko.sawada@2ndquadrant.com> wrote:
>
> On Thu, 6 Feb 2020 at 16:53, Amit Langote <amitlangote09@gmail.com> wrote:
> >
> > On Thu, Feb 6, 2020 at 4:31 PM Michael Paquier <michael@paquier.xyz> wrote:
> > > On Thu, Feb 06, 2020 at 04:25:47PM +0900, Amit Langote wrote:
> > > > About the implementation, how about defining a static inline function,
> > > > say is_user_object(), next to FirstNormalObjectId's definition and
> > > > make pg_is_user_object() call it?  There are a few placed in the
> > > > backend code that perform the same computation as pg_is_user_object(),
> > > > which could be changed to use is_user_object() instead.
> > >
> > > FWIW, if we bother adding SQL functions for that, my first impression
> > > was to have three functions, each one of them returning:
> > > - FirstNormalObjectId
> > > - FirstGenbkiObjectId
> > > - FirstNormalObjectId
> >
> > Did you miss FirstBootstrapObjectId by any chance?
> >
> > I see the following ranges as defined in transam.h.
> >
> > 1-(FirstGenbkiObjectId - 1): manually assigned OIDs
> > FirstGenbkiObjectId-(FirstBootstrapObjectId - 1): genbki.pl assigned OIDs
> > FirstBootstrapObjectId-(FirstNormalObjectId - 1): initdb requested
> > FirstNormalObjectId or greater: user-defined objects
> >
> > Sawada-san's proposal covers #4.  Do we need an SQL function for the
> > first three?  IOW, would the distinction between OIDs belonging to the
> > first three ranges be of interest to anyone except core PG hackers?
>
> Yeah I thought of these three values but I'm also not sure it's worth for users.
>
> If we have these functions returning the values respectively, when we
> want to check if an oid is assigned during initdb we will end up with
> doing something like 'WHERE oid >= pg_first_bootstrap_oid() and oid <
> pg_first_normal_oid()', which is not intuitive, I think. Users have to
> remember the order of these values.
>

Attached the updated version patch that includes regression tests. And
I have registered this to the next commit fest.

Regards,

-- 
Masahiko Sawada            http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services