[ZODB-Dev] BerkleyStorage

[Chris Withers]

Michel Pelletier wrote:
> 
> Chris Withers wrote:
> >
> > > My tests indicate that Full storage (i.e undoable, versioning) is
> > > about twice as slow as FileStorage.  Jim thought that that wasn't too
> > > bad.  :)  I haven't spent any time on performance profiling, but will
> > > likely do that after the 1.0 final release.
> >
> > Probably a stupid question, but how come?
> 
> There's an entire extra layer of complex software between you and the
> database file.

Ah...

> > Does this affect reads from the DB itself or reads from the Zope object
> > cache as well?
> 
> I don't know about the first, but the object cache is above the storage
> object; its speed should not be effected.

Cool...

> > In what ways would this performance decrease affect the overall performance
> > of Zope? (I suppose the main thing I care about is will there be a noticable
> > increase in the time Zope takes to deliver a page?)
> 
> Probably not, unless your can notice hundreths of milliseconds.  Really,
> the question is too broad.  There are many, many more circumstances that
> effect Zope's efficiency.  Compared to the amount of computation that
> Zope's security model must do, the extra time that BDB adds is probably
> a wash.

Fair enough. If I'm right in assuming that BerkleyStorage is destined to be the
'production default' storage, then if there's a speed problem someone will find
some way to fix it :-)

thanks,

Chris