Re: Synchronizing slots from primary to standby

Hi,

On Wed, Feb 28, 2024 at 06:48:37AM +0000, Zhijie Hou (Fujitsu) wrote:
> On Wednesday, February 28, 2024 2:38 PM Bertrand Drouvot <bertranddrouvot(dot)pg(at)gmail(dot)com> wrote:
> > On Wed, Feb 28, 2024 at 08:49:19AM +0530, Amit Kapila wrote:
> > > On Mon, Feb 26, 2024 at 9:13 AM shveta malik <shveta(dot)malik(at)gmail(dot)com>
> > wrote:
> > > >
> > > > On Fri, Feb 23, 2024 at 7:41 PM Bertrand Drouvot
> > > > <bertranddrouvot(dot)pg(at)gmail(dot)com> wrote:
> > > > >
> > > > > Hi,
> > > > > > I think to set secure search path for remote connection, the
> > > > > > standard approach could be to extend the code in
> > > > > > libpqrcv_connect[1], so that we don't need to schema qualify all the
> > operators in the queries.
> > > > > >
> > > > > > And for local connection, I agree it's also needed to add a
> > > > > > SetConfigOption("search_path", "" call in the slotsync worker.
> > > > > >
> > > > > > [1]
> > > > > > libpqrcv_connect
> > > > > > ...
> > > > > > if (logical)
> > > > > > ...
> > > > > > res = libpqrcv_PQexec(conn->streamConn,
> > > > > >
> > > > > > ALWAYS_SECURE_SEARCH_PATH_SQL);
> > > > > >
> > > > >
> > > > > Agree, something like in the attached? (it's .txt to not disturb the CF bot).
> > > >
> > > > Thanks for the patch, changes look good. I have corporated it in the
> > > > patch which addresses the rest of your comments in [1]. I have
> > > > attached the patch as .txt
> > > >
> > >
> > > Few comments:
> > > ===============
> > > 1.
> > > - if (logical)
> > > + if (logical || !replication)
> > > {
> > >
> > > Can we add a comment about connection types that require
> > > ALWAYS_SECURE_SEARCH_PATH_SQL?
> >
> > Yeah, will do.
> >
> > >
> > > 2.
> > > Can we add a test case to demonstrate that the '=' operator can be
> > > hijacked to do different things when the slotsync worker didn't use
> > > ALWAYS_SECURE_SEARCH_PATH_SQL?
> >
> > I don't think that's good to create a test to show how to hijack an operator
> > within a background worker.
> >
> > I had a quick look and did not find existing tests in this area around
> > ALWAYS_SECURE_SEARCH_PATH_SQL / search_patch and background worker.
>
> I think a similar commit 11da970 has added a test for the search_path, e.g.

Oh right, thanks for sharing!

But do we think it's worth to show how to hijack an operator within a background
worker "just" to verify that the search_path works as expected?

I don't think it's worth it but will do if others have different opinions.

Regards,

--
Bertrand Drouvot
PostgreSQL Contributors Team
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