[ZODB-Dev] BerkleyStorage

[Michel Pelletier]

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.
 
> 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.

> 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.

-Michel