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A comment on 3 billion items in Java Map with 16 GB RAM. Parent comment

Re:3 billion items in Java Map with 16 GB RAM by cfieber on Sunday November 11, 2012 @03:35PM (#4770501)
It is kind of a dumb test to do 'new HashMap' with the default initialCapacity then cram stuff into it in a tight loop.

It is basically testing constant rehashes which is obviously going to generate a ton of garbage

I suspect the default collection implementations would perform significantly better if they were used correctly

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Re:3 billion items in Java Map with 16 GB RAM by zorked on Sunday November 11, 2012 @05:09PM (#4770741)
They still suck even if you set a large initialCapacity.
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