Re: currval() race condition on server?

Tom Lane wrote:
> Adriaan Joubert <a(dot)joubert(at)albourne(dot)com> writes:
>
>>For some bookkeeping purposes I need the new audit number back from the
>>update, so I submit a prepared statement through jdbc of the form
>>
>>UPDATE A SET ....; SELECT currval('ip_audit_seq');
>
>
> It's not possible to put two SQL commands into one prepared statement
> --- at least not for the normal server-side meaning of "prepared statement".
> I dunno what the JDBC driver is doing with this, but I wonder if it's
> silently dropping the UPDATE part :-(

The driver should split this query on the semicolons and send
Parse/Bind/Execute for each part, followed by a Sync at the end. If it
ends up using named statements due to JDBC statement reuse, it should
use a different name for each part. Of course there might be unknown
bugs in there, but it has been designed to handle this sort of compound
statement..

To the OP: Is autocommit on or off? Can you reproduce the problem with a
URL parameter of loglevel=2 and see what it looks like? (that'll
generate a trace protocol-level messages)

-O