On 7/24/11 4:08 PM, Keith Roberts wrote:
On Sun, 24 Jul 2011, R P Herrold wrote:
By using a hash, we remove those constraints, and also gain the virtuous effect for free of self-organizing a relatively level dispersion of files to the destination directories
Not followed the whole thread, but a SQL database index of the actual picture files, giving the path into the directory structure. Would that work?
You introduce new issues where the name in the database can't be managed atomically with the name in the directory that way. Consider what might happen with concurrent operations trying to add different files with the same name - or perhaps an add and delete at the same times.
And it still doesn't help with the real problem unless you do something to break up the large directory. Unix-like filesystems guarantee atomic operations in filename manipulation, so every time you try to create a file, the system must check that the name does not already exist, find an empty slot for the name and insert it with the directory locked against other changes until that is complete. Filesystems that index directories can help with the lookup, with the tradeoff that additions require an index update.