Re: RLS policy not getting honer while pg_dump on declarative partition

Amit,

* Amit Langote (Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp) wrote:
> On 2017/06/17 9:20, Stephen Frost wrote:
> > I think we could certainly consider if this behavior is desirable in a
> > system which includes partitioning instead of inheritance,
>
> Do we want CREATE POLICY foo ON parent creating the policy objects for all
> the partitions? That is, cascade the policy object definition?

That seems to be what the OP is suggesting we should have. I'm
certainly not convinced that we actually do want that though. There are
clear reasons why it doesn't make sense for inheritance that aren't an
issue for partitions (for one thing, we don't have to worry about the
visible columns being different between the partitioned table and the
partitions), but that doesn't necessairly mean we want to make this
different for partitions vs. inheritance.

In any case though, I do tend to feel that it's rather too late to
consider changing things for PG10 in this area, even if we all felt that
it was the right/correct thing to do, which isn't clear.

> > but if we
> > wish to do so then I think we should be considering if the GRANT system
> > should also be changed as I do feel the two should be consistent.
>
> IIUC, you are saying here that GRANT should be taught to cascade the
> permission grant/revokes to partitions.

What I'm saying here is that the way GRANT works and the way policies
are applied to partitioned tables should be consistent with each other.

> Also, the somewhat related nearby discussion about dumping the partition
> data through the root parent will perhaps have to think about some of
> these things. Dumping data through the root table will take care of the
> problem that Rushabh is complaining about, because only rows visible per
> the parent's policies would be dumped. Of course then the the set of rows
> dumped will be different from what it is today, because one would expect
> that a different set of policies would get applied - the root table's
> policies when dumping data through it vs. the individual partitions'
> policies when dumping data per partition.

While somewhat related, I don't think we should allow concerns about
pg_dump to drive what we're doing in the backend. If pg_dump isn't
smart enough to allow different ways to dump the data out given the
considerations for what the backend supports/does, then we should add
new features to pg_dump, not reconsider what we're doing in the backend.

Thanks!

Stephen