Re: Overwrite pg_catalog?

Juliano:

On Thu, Dec 1, 2016 at 12:16 PM, Juliano <jplinux(at)protonmail(dot)com> wrote:
> I tried to restore pg_catalog to my new database, but the existing
> pg_catalog can't be overwritten or dropped, and postgres auto creates
> pg_catalog when I create a new DB.

This is because, in general, pg_catalog is maintained by DML
statements, restoring it is not going to do what you think.

I.e., if you create a table, a row goes into pg_class, but if you
somehow manage to insert into pg_class a table is not properly created
( more things need to be done ).

Copying pg_catalog from one db to other is like trying to copy the
root dir and FAT from one floppy ( how old fashioned ) to other, it
cannot be done with normal tools and probably won't do what you think
it does.

> So, there is a way to restore the pg_catalog to a new database?

Probably not, but this has the faint smell of http://xyproblem.info/ ,
what are you truing to achieve by doing that?

Francisco Olarte.