Thank you, that cleared things up perfectly. I was familiar with the bit from perldata about pre-sizing large arrays for efficiency (although it describes the gain as "miniscule," which is clearly not the case here), but I assumed that meant the CPU efficiency of not requiring repeated re-allocations of memory -- the doubling you speak of. I didn't realize that those doublings were done in new memory rather than appending to what was already allocated, causing inefficiency memory-wise too. And I hadn't thought about the fact that two arrays exist at once in the first method, but it makes perfect sense.

Aaron B.
Available for small or large Perl jobs; see my home node.

In reply to Re^4: how apply large memory with perl? by aaron_baugher
in thread how apply large memory with perl? by xiaoyafeng

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