[ZODB-Dev] ZEO and BDBMinimalStorage

[Jeremy Hylton]

On Wed, 2003-07-09 at 17:46, Barry Warsaw wrote:
> On Wed, 2003-07-09 at 17:23, fzachman wrote:
> 
> > I've looked, and BDBMinimalStorage indeed doesn't have a lastTransaction
> > method (though FullStorage does...)  Is this a problem in the
> > MinimalStorage or in the way the StorageServer is dealing with
> > lastTransaction?  It looks like it's required (to get the thread id in
> > tpc_finish) so it should probably be implimented in MinimalStorage but
> > I'm not sure what that tid is used for in the calling functions...
> 
> BDBMinimalStorage could, and possibly should, implement
> lastTransaction(), although note that because it doesn't keep object
> revisions, the last transaction is the /only/ transaction that can be
> accessed.  It should be easy to add by refactoring a bit of code into
> the base class.
> 
> I'm not sure if that will help minimal storage to be useful in ZEO or
> not though.  Maybe Jeremy can speak to that.

ZEO requires that the storage implement lastTransaction().  It is used
for cache consistency, and has nothing to do with undo or other
multiple-revision features.

Jeremy