Horton

Re: ExecRTCheckPerms() and many prunable partitions

Tom Lane <tgl@sss.pgh.pa.us>

View thread View on postgr.es
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Amit Langote <amitlangote09@gmail.com>
Cc: David Rowley <dgrowleyml@gmail.com>, Greg Stark <stark@mit.edu>, Zhihong Yu <zyu@yugabyte.com>, Julien Rouhaud <rjuju123@gmail.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-10-04T03:54:27Z
Lists: pgsql-hackers 
Amit Langote <amitlangote09@gmail.com> writes:
> On Thu, Jul 28, 2022 at 6:18 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> ... One more thing: maybe we should rethink where to put
>> extraUpdatedCols.  Between the facts that it's not used for
>> actual permissions checks, and that it's calculated by the
>> rewriter not parser, it doesn't seem like it really belongs
>> in RelPermissionInfo.  Should we keep it in RangeTblEntry?
>> Should it go somewhere else entirely?  I'm just speculating,
>> but now is a good time to think about it.

> I've kept extraUpdatedCols in RangeTblEntry in the latest patch, but
> perhaps it makes sense to put that into Query?

That's got morally the same problem as keeping it in RangeTblEntry:
those are structures that are built by the parser.  Hacking on them
later isn't terribly clean.

I wonder if it could make sense to postpone calculation of the
extraUpdatedCols out of the rewriter and into the planner, with
the idea that it ends up $someplace in the finished plan tree
but isn't part of the original parsetree.

A different aspect of this is that putting it in Query doesn't
make a lot of sense unless there is only one version of the
bitmap per Query.  In simple UPDATEs that would be true, but
I think that inherited/partitioned UPDATEs would need one per
result relation, which is likely the reason it got dumped in
RangeTblEntry to begin with.

			regards, tom lane

Commits

  1. Add a test case for a316a3bc

  2. Correctly set userid of subquery relations' child rels

  3. Fix buggy recursion in flatten_rtes_walker().

  4. Remove some dead code in selfuncs.c

  5. Update outdated comment in ApplyRetrieveRule

  6. Rework query relation permission checking

  7. Generalize ri_RootToPartitionMap to use for non-partition children

  8. Stop accessing checkAsUser via RTE in some cases

  9. Add 'missing_ok' argument to build_attrmap_by_name