Subject Re: [Firebird-Java] Maximum number of items in batch
Author Roman Rokytskyy
> I'll see if I can link in a free profiler when I get a chance. I'm
> guessing the problem is b.
> One free improvement would be the result list (and the batch list):
> ( the relevant line in the following graph is ArrayList best-case, as we
> know the size to preallocate)
> Try:
> List results = new ArrayList[batchList.size()];
> There is less memory overhead (ArrayList doesn't store pointers to
> previous and next), memory allocation is more efficient (it's all done
> at one time), and it's fail-fast (if there isn't enough memory, it'll
> fail at the beginning before doing any more work)[of course, this
> ignores the memory allocated with each new Integer].

True, I should have used ArrayList, or even int[]. However we are talking
about improving the memory usage from 8 to 24 bytes per item in batch, in
your case something ~3 MB. The storage of that 160,000 items takes at least
something ~300-500 MB (or maybe even more). If your application is crashing
because of not being able to allocate 3 MB right after allocating 300-500
MB, I would first consider reviewing the application.

Anyway, please fill the bug report and I will clear that place in the next

> BTW, is backupVars being used?

Nope. Some refactoring artifact. 24 bytes more.