Re: currval question

Andy, 

I don't know exactly what's under the hood, but I know that currval() won't
even return a result unless you've used nextval() in your session. If
currval() did not operate solely within the scope of the session, it stands
to reason that it would return a result... It's behavior (from the driver's
seat) is consistent with a well conceived concurrency model. This should be
easy enough to test with a couple of terminals. My money is on Postgres! :)

Regards,
Garo. 

on 9/16/02 3:14 PM, Andy Kriger at akriger@greaterthanone.com wrote:

> I am trying to get the last value updated by an column auto-incrementing
> with nextval(). In MySQL, you'd use LAST_INSERT_ID() - in Postgre, currval()
> appears to do the trick.
> 
> Is this maintained on a per-connection basis? For example, user A inserts
> and the nextval() updates to 5, user B does 2 inserts, updating nextval() to
> 7. When user A calls currval() they should get 5 if the updates are per-cnx.
> What does psql do under the hood here?
> 
> thx
> a
> 
> 
> 
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