[ZODB-Dev] how big can a ZODB get?

[Jim Fulton]

Victor Ng wrote:
> Ok - so documentation is sparse, is there a set classes in the ZODB
> that I should look at for tuning?  I've generated an epydoc for ZODB
> 3.3 to help me poke through the code as a starting guide for myself.

You want to tune the cache_size parameter given to the constructor
to the DB class, when creating your database object in Python.
This parameter sets a *target* cache size, in number of objects,
per connection.  It is very imprecise because:

- Cache cleaning only happens at transaction boundaries
   and other discrete points, so it's not uncommon for the
   object cache to grow much larger than the target size.

- The unit, number of objects, is loosly correlated to
   memory consumption.

Jim

> vic
> 
> 
> On Wed, 12 Jan 2005 11:03:27 -0500, Jim Fulton <jim at zope.com> wrote:
> 
>>Victor Ng wrote:
>>
>>>Thanks for the info Jim, where can I find information on ZODB tuning?
>>
>>Alas, documentation is a major problem with ZODB.  I'm sure there
>>are sources out there. Hopefully, google is your friend.  Probably
>>most of the information relares to ZODB in Zope.
>>
>>
>>>I'm running ZODB 3.3 right now and I'm not sure where to start looking
>>>for the 'knobs' I need to turn.   I found one reference to tuning the
>>>ZODB from Jeremy Hylton from 2002 :
>>>
>>>http://mail.zope.org/pipermail/zodb-dev/2002-November/003675.html
>>>
>>>But that's about it.  Are there separate tuning docs when using the
>>>ZEO with ZODB?  Where can I find information?
>>
>>I don't have any pointers at hand.  Hopefully, someone else
>>here does.
>>
>>We really need to make a concerted effort on documentation.
>>
>>Jim
>>
>>--
>>Jim Fulton           mailto:jim at zope.com       Python Powered!
>>CTO                  (540) 361-1714            http://www.python.org
>>Zope Corporation     http://www.zope.com       http://www.zope.org
>>


-- 
Jim Fulton           mailto:jim at zope.com       Python Powered!
CTO                  (540) 361-1714            http://www.python.org
Zope Corporation     http://www.zope.com       http://www.zope.org