On 12/04/2009 09:32 PM, Chris Webb wrote: > A random off-the-wall suggestion: I wonder if it would be possible to use a > filesystem directory tree to store the catalogue information instead of a > single large database file or the current large block file. rename(2), > link(2) and even symlink(2) are atomic on all POSIX filesystems, and are > presumably optimised to be reasonably fast (?). If instead of overwriting > part of a large file, we wrote a new tiny file and then move() it over the > top of the original tiny file, we get atomic behaviour for free pretty much > everywhere. If I understand you correctly, it make us access many tiny files when client read/write large sequential data, right? It results in a very low I/O thoughput, I think. But, using rename, link and symlink may be worth considering. Thanks for a good suggestion. Regards, MORITA Kazutaka |