[Neo-users] ZODB minimal version

[Vincent Pelletier]

Hi.

In the upcoming changes, the minimum required ZODB version to run NEO on will 
be increased to ~3.10 (as is used in Zope 2.12 for example).

The reason for this is the need for the IMVCCStorage interface (and more 
importantly, the mechanism behind it) to finally overcome the months-old 
performance problem introduced in r2286, in response to the discovery of a 
transaction isolation bug.

A few words on the solution:
To overcome this bug and the performance problem, I decided to implement MVCC 
at Storage level (ie neo.client.Storage), so all "load" call will end up doing 
a "loadBefore" call with some maximum TID.
To make this work efficiently, client-side storage-level caching will be 
extended to support the associated kind of workload.

Regards,
-- 
Vincent Pelletier