[Zope-DB] ZSQL Caching

[Dieter Maurer]

Andy McKay writes:
 > We were discussing ZSQL caching and work, and we wanted to debug the
 > contents of our cache, so I through together a quick method that cleans up
 > the cache a little and adds a Cache tab. There you can see the contents of
 > the cache and flush it.
 > 
 > For quick debugging we found it quite useful.
Be careful:

  The cache is maintained in "_v_" attributes.
  These attributes are thread local. If you flush one in a given
  thread, this does not mean that the instances in the other
  threads are flushed, too. Instead, you cannot be sure
  that a different request does not get stale data...

This fact led me to the implementation of ZCCSQL methods
(Cache Controlled SQL Methods). See

  <http://www.dieter.handshake.de/pyprojects/zope>



Dieter