[Zope-DB] ZSQL Caching

[Andy McKay]

> 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...

Absolutely, its designed for debugging only rather than a serious
examination of the cache.

Cheers.
--
  Andy McKay.


----- Original Message -----
From: "Dieter Maurer" <dieter@handshake.de>
To: "Andy McKay" <andym@ActiveState.com>
Cc: <zope-db@zope.org>
Sent: Wednesday, October 31, 2001 1:14 PM
Subject: Re: [Zope-DB] ZSQL Caching


> 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
>