Bruce Momjian wrote:
> Robert Haas wrote:
>> On Wed, Jan 28, 2009 at 6:57 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> Hmm. If that's the expected application environment then the patch as
>>> proposed has fatal performance problems anyway, for lack of a way to
>>> get rid of no-longer-referenced pg_security rows. We had been led to
>>> understand that there wouldn't be all that many distinct labels in use,
>>> but this seems to imply that there are going to be $bignum of them.
>>> That changes pg_security leakage from a can-live-with-for-first-cut
>>> issue to a must-fix-to-be-credible issue.
>> It's worth noting that this is yet another thing that is mostly a
>> problem in the context of row-level security. It seems to me that if
>> security labels are only applied to tables and columns, then it will
>> be possible to scan the whole database relatively quickly and find all
>> the labels that are still in use, probably without breaking a sweat.
>> On the other hand, when you have row-level security, it gets a lot
>> harder.
>
> If we are not labeling every row, why not just use a TEXT column without
> using an OID to reference pg_security; there aren't that places,
> pg_class, pg_attribute, etc, i.e. they are not on every data row.
We should not assume every row are not labeled forever, at least.
It will lose expandability soon.
Thanks,
--
OSS Platform Development Division, NEC
KaiGai Kohei <kaigai@ak.jp.nec.com>
