Subject: Re: Non-superuser subscription owners

From: Jeff Davis <[email-masked]>
Date: Fri, 07 Jan 2022 23:38:31 -0800

On Wed, 2021-12-15 at 12:23 -0800, Mark Dilger wrote:
> > On Nov 24, 2021, at 4:30 PM, Jeff Davis <[email-masked]> wrote:
> > 
> > We need to do permission checking for WITH CHECK OPTION and RLS.
> > The
> > patch right now allows the subscription to write data that an RLS
> > policy forbids.
> 
> Version 4 of the patch, attached, no longer allows RLS to be
> circumvented, but does so in a course-grained fashion.

Committed.

I tried to do some performance testing to see if there was any impact
of the extra catalog + ACL checks. Logical replication seems slow
enough -- something like 3X slower than local inserts -- that it didn't
seem to make a difference.

To test it, I did the following:
  1. sent a SIGSTOP to the logical apply worker
  2. loaded more data in publisher
  3. made the subscriber a sync replica
  4. timed the following:
    a. sent a SIGCONT to the logical apply worker
    b. insert a single tuple on the publisher side
    c. wait for the insert to return, indicating that logical
       replication is done up to that point

Does anyone have a better way to measure logical replication
performance?

Regards,
	Jeff Davis