Re: Pl/Java - next step? - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Pl/Java - next step?
Date
Msg-id 200402282247.i1SMlcG21001@candle.pha.pa.us
Whole thread Raw
In response to Re: Pl/Java - next step?  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:
> "Thomas Hallgren" <thhal@mailblocks.com> writes:
> > ** 4. Make the postmaster spawn threads rather than processes **
> > I know this is very controversial and perhaps I should not bring it up at
> > all. But then again, why not? Most readers are open-minded right?
> 
> It's been considered and rejected before, and pljava isn't going to tilt
> the scales.  In fact, the main thing that bothers me about your
> description of JNI is "Java uses multithreading wether you like it or
> not".  I am very afraid of what impact a JVM will have on the stability
> of the surrounding backend.
> 
> Other than that fear, though, the JNI approach seems to have pretty
> considerable advantages.  You listed startup time as the main
> disadvantage, but perhaps that could be worked around.  Suppose the
> postmaster started a JVM --- would that state inherit correctly into
> subsequently forked backends?
> 
> Also, regarding your option #3 (do both), do you really think something
> different is going to happen in practice?  The developers of the other
> implementation aren't likely to give it up just because yours exists.

As I understand it, the JNI approach has one JVM per backend using java,
while the Java/remote approach uses a single JVM for all backends and
isolates them via classes.

JNI says function execution will be faster and cleaner, while
Java/remote feels system resource usage and startup time will be less.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
359-1001+  If your life is a hard drive,     |  13 Roberts Road +  Christ can be your backup.        |  Newtown Square,
Pennsylvania19073
 


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