"A.M." <agentm@themactionfaction.com> wrote:
> On Apr 27, 2009, at 5:39 PM, Dimitri Fontaine wrote:
>> Le 27 avr. 09 à 23:32, A.M. a écrit :
>>> When will postgresql offer "global" temporary tables with data
>>> which are shared among sessions? Such tables are great for
>>> transient data such as web session data where writing to the WAL is
>>> a waste. (On DB startup, the tables would simply be empty.) We're
>>> currently stuck with the memcached plugin which makes it impossible
>>> to use database constructs such as foreign keys against the
>>> temporary data.
>>
>>
>> If using 8.3 you can SET LOCAL synchronous_commit TO off; for web
>> session management transactions, it'll skip the WAL fsync'ing, which
>> is already a good start.
>
> That's pretty close, but it's not table specific and wouldn't let us
> to reliably mix transient data changes with real data changes.
Yeah, we have a dozen or so tables we use with the pattern you
describe; so the feature you describe would also have some value for
us. To avoid confusion, we don't refer to these as "temporary
tables", but rather as "permanent work tables". Again, I can't
comment on practical issues regarding implementation; but it would be
a "nice feature" to add some day. The tricky bit would be to figure
out how to ensure that it got cleaned up properly, especially if the
PostgreSQL went down or client processes wend down before tidying up.
-Kevin