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From "Thomas Mueller" <thomas.tom.muel...@gmail.com>
Subject Re: NGP: Prototyping
Date Thu, 15 Nov 2007 09:07:15 GMT
Hi,

A few remarks about the current NGP prototype:

java.nio.ByteBuffer (FileJournal / MediumRecord)
Just curious, did you run some tests, is it faster than using
RandomAccessFile.read?

FileChannel.map
My experience with memory mapped files is: it is fast, but
problematic. The biggest problem (for me) is: there is no way to unmap
a file. That means it is not possible to truncate, rename, or delete a
file that was once mapped. See:
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4724038

Journal:
"A record is never modified or removed once it has been added to a
journal.". I agree, if there is a mechanism to removing old journal
files.

Thomas

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