[Zope] Re: database conflict errors

[Dieter Maurer]

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