On Sat, Apr 27, 2013 at 3:51 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> On Sat, Apr 27, 2013 at 3:33 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> Um, wait, it's *not* in pg_class now, and what I was about to do was
>>> go put it there. Is there a typo in the above para, or are you saying
>>> you don't like either approach? If the latter, what concept have you
>>> got for an eventual implementation?
>
>> If we're going to have it at all, I'd like to make it a flag in the
>> page header on page 0, or maybe have a dedicated metapage that stores
>> that detail, and perhaps other things.
>
> I cannot say that I find that idea attractive; the biggest problem with
> it being that updating such a state flag will be nontransactional,
> unless we go to a lot of effort to support rollbacks. ISTM that the
> scannability property is a perfectly normal relation property and as
> such *ought* to be in the pg_class row, or at worst some other catalog
> entry. Why do you think differently?
Mostly because of the issue with unlogged tables, I suppose. If
you've got a reasonable idea how to do catalog updates on restart,
though, I could probably be convinced to yield to that.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company