From: thomas at tada.se (Thomas Hallgren) Date: Mon, 27 Mar 2006 16:15:38 +0200 Subject: [Pljava-dev] [HACKERS] Shared memory In-Reply-To: References: <4423CF32.3060406@tada.se> <20060324125851.GC8718@svana.org> <4427A8F1.3020009@tada.se> <20060327104506.GB30791@svana.org> <4427DF17.7040700@tada.se> Message-ID: <4427F38A.6090408@tada.se> Rakesh Vidyadharan wrote: > I agree with your view of connection pools. The only time I wished > that PL/Java did not have such a "heavy" initialisation requirement > was when I needed to use a Java stored procedure from C (it was too > trivial to explore using a connection pool). I ended up writing an > equivalent stored procedure in pgsql. This may be a major issue for > some people, since one of the main benefits of using stored procedures > is that your database logic becomes available to multiple technologies. Good point. > > In my view the main benefit that may be derived form using a shared > JVM is that you may be able to support more connections. Maybe you > can just wait for the multi-tasking JVM to arrive on the scene. I am > not sure how far the Java committee is on that, but there has been > talk of developing one for quite a while now. > I think you mean the JSR121, where many JVM's can share resources by running as "Java Isolates" in a MVM?. Unfortunately that will not help much. A PostgreSQL backend process will still need to use ipc in order to talk to the MVM process. What would help is if multiple JVM's, each running as a separate process, could share a lot of resources but I haven't seen any viable effort in that direction. I doubt it's doable without major parts of the JVM being built into the kernel. Regards, Thomas Hallgren