Re: Schema variables - new implementation for Postgres 15

so 18. 11. 2023 v 15:54 odesílatel Dmitry Dolgov <9erthalion6(at)gmail(dot)com>
napsal:

> > On Sat, Nov 18, 2023 at 02:19:09PM +0100, Pavel Stehule wrote:
> > > Would it be a problem to make pg_session_variables inspect the catalog
> > > or something similar if needed?
> > >
> >
> > It can be very easy to build pg_session_variables based on iteration over
> > the system catalog. But I am not sure if we want it.
> pg_session_variables()
> > is designed to show the variables from session memory, and it is used for
> > testing. Originally it was named pg_debug_session_variables. If we
> iterate
> > over catalog, it means using locks, and it can have an impact on
> isolation
> > tests.
>
> I see, thanks for clarification. In the end one can check the catalog
> directly of course, is there any other value in this function except for
> debugging purposes?
>

I have no idea how it can be used for different purposes. Theoretically it
can be used to check if some variable was used (initialized) in a session
already. But for this purpose it is not too practical, and if there will be
some request for this functionality, then we can write a special function
for this purpose. But I don't know any actual use cases for this.

> As a side note, I'm intended to go one more time through the first few
> patches introducing the basic functionality, and then mark it as ready
> in CF. I can't break the patch in testing since quite long time, and for
> most parts the changes make sense to me.
>

Thank you very much, for testing, comments, and all other work.

I marked pg_session_variables function as PARALLEL RESTRICTED, and did
rebase

Regards

Pavel