Re: global temporary tables

On Apr 24, 2010, at 10:02 PM, Tom Lane wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> Pushing it into the RelFileNode has some advantages in terms of being
>> able to get at the information from everywhere, but one thing that
>> makes me think that's probably not a good decision is that we somtimes
>> WAL-log relfilenodes.  And WAL-logging the value of the isTemp flag is
>> a waste, because if we're WAL-logging, it's zero.
>
> Yeah.  I think we also use RelFileNode as a hash tag in places, and
> so adding a bool to it would be problematic for a couple of reasons:
> possibly uninitialized pad bytes, and uselessly incorporating more bytes
> into the hash calculation.

Do we need to hash it that frequently? Do we insert tons of them into WAL? Worrying about those cases smells like
prematureoptimization, but admittedly I don't have enough knowledge here... 
--
Jim C. Nasby, Database Architect                   jim@nasby.net
512.569.9461 (cell)                         http://jim.nasby.net