Florent Guillaume wrote at 2006-6-30 02:46 +0200:
...
that's interesting. I did a test once to see what effect it would have to add objects with a completely random id to a BTree folder (OOBTree in that case) instead of using the object's type nam and add a number at the end - and the result was the opposite in term of read performance. Looking up keys was much faster if the ids followed a pattern like:
- something-1 - something-2 ...
Sure, in single-threaded mode this will decrease performance because the keys are spread randomly among all the buckets so many more buckets get written.
But in multi-threaded mode, this very spreading leads to better conflict resolution behavior.
But still can reduced performance... That's why the catalog uses the initial id randomly but then assigns id's (within a single thread) sequentially. -- Dieter