>
> It's news to me that the Java VM supports an object image. Or that any 
> real-world system on Java would just load a snapshot of *all* its data 
> and save it *in whole* later - I sincerely doubt that.
>
> - Bert -
>
I wrote a system which held a substantial data set in image with no 
problems (this was ST/X).

The biggest problem I had was with stdio.h being limited to 255 open 
file descriptors in certain situations on Solaris. As a work around I 
had to open 256 dummy file descriptors, then open the 700-1000 file 
descriptors that I wanted to use. Then close the dummy file descriptors, 
so as to leave some in the range 0-255 available for those parts of the 
system that required them.

Another team tried a similar project in perl and another team followed 
suit in java. Last I heard they reimplemented from scratch in C++. The 
java system took a farm of machines to run it.  Following this 
experience I have no confidence in the java vm, or associated 
technologies being able to run anything of any size or complexity.

Smalltalk can load a simulation of over 1000 interacting telecoms units 
with a full simulation of all their configurations, cards, alarms, etc, 
and load and have running that simulation in about 20 seconds. The time 
it takes to load a 200-400Mb image. Which is not long on a big expensive 
sun server machine.

I cant imagine even attempting the same in java without requiring a 
database backend and all of the overhead that that would entail.

Overall Squeak's vm may not be as fast as ST/X, but I think it does a 
pretty good job.

Keith



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