[ZODB-Dev] Getting rid of ZODB versions (was Re: [ZWeb] Are Versions evil?)

[Jim Fulton]

Christian Robottom Reis wrote:
> On Thu, Jul 15, 2004 at 05:18:37PM -0400, Jim Fulton wrote:
> 
>>I don't think anyone find versions useful in cases where
>>locks matter.  With versions, if you get resource contention,
>>someone loses.
>>
>>Long-running subtransactions as I'm proposing would rely on mult-version
>>concurrency control, rather than locks.  In either case, if you have
>>resource contention, you are probably out of luck.
> 
> 
> Locks are important, however, in cases such as generating unique IDs
> based on integer attribtues in a database.

I don't know what this is.

 > This is something we never
> managed to sort out in IndexedCatalog, and I wonder if anyone else ever
> has.

In the regular catalog, we pick ids and let normal time-stamp-based
concurrency control tell us when there is a conflict.

The database itself uses a short-lived lock to generate oids.

Jim


-- 
Jim Fulton           mailto:jim at zope.com       Python Powered!
CTO                  (540) 361-1714            http://www.python.org
Zope Corporation     http://www.zope.com       http://www.zope.org