[ZODB-Dev] _p_resolveConflicts

[Jim Fulton]

"Randall F. Kern" wrote:
> 
> OH!  That would be it then :(
> 
> So is there any way (other than using an external storage medium) to
> write a counter that will never cause a retry?  It's a major hotspot in
> my system.

Hm, now that you mention it, there's a hook that
will let you do this::

    def _p_independent(self):
        # My state doesn't depend on or materially effect the state of
        # other objects.
        return 1

See BTrees/Length.py.  This disables the consistency check for
the object that implements the hook.

Jim
 
> -Randy
> 
> > -----Original Message-----
> > From: Jim Fulton [mailto:jim@digicool.com]
> > Sent: Thursday, August 02, 2001 12:51 PM
> > To: Randall F. Kern
> > Cc: zodb-dev@zope.org
> > Subject: Re: [ZODB-Dev] _p_resolveConflicts
> >
> >
> > "Randall F. Kern" wrote:
> > >
> > > Although my hook (_p_resolveConflicts) is called and is
> > returning the
> > > proper state, the transactions are still being retried :(
> > >
> > > Does the default FileStorage in Zope 2.4.0 support conflict
> > resolution
> > > or not?
> >
> > It does.
> >
> > Note that conflict errors can be detected when reading data.
> > Conflict resolution cannot resolve conflicts detected when
> > reading.  :(
> >
> > We need to add full support for "multi-version concurrency
> > control", which will allow us to avoid read conflicts by
> > reading non-current but consistent data.
> >
> > Jim
> >
> > --
> > Jim Fulton           mailto:jim@digicool.com   Python Powered!
> > Technical Director   (888) 344-4332            http://www.python.org
> > Digital Creations    http://www.digicool.com   http://www.zope.org
> >
> 
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--
Jim Fulton           mailto:jim@digicool.com   Python Powered!        
Technical Director   (888) 344-4332            http://www.python.org  
Digital Creations    http://www.digicool.com   http://www.zope.org