[Pljava-dev] pl/java and concurrency

Hi Richard,

Each connection in PostgreSQL runs in a process of its own. It's not a
multi threaded server architecture. This means that each connection will
have a JVM of its own which means that there's no real concurrency.

If code inside a trigger spawns multiple threads that in turn performs
database accesses using the internal PL/Java jdbc driver, then PL/Java
will synchronize those calls and only allow one at a time. It has to be
that way since they all share the same connection (and the same
transaction).

HTH,
Thomas Hallgren

On 2012-04-29 00:02, Welty, Richard wrote:
>
> i'm looking a pl/java as a possible implementation language for a
> trigger function.
>
> the trigger is going to need to do a couple of selects, build an xml
> string and then issue an http request.
> it has the potential to be rather busy.
>
> i understand the reason why entry points need to be statics, but i'd
> like to understand how pl/java
> deals with concurrency. could someone please outline how this works?
>
> the solution will be running on amazon ec2 linux instances, postgresql
> 9.1.3. the installed jdk is
> openjdk 1.6
>
> thanks,
> richard
>
>
>
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