John Goerzen wrote:

Hi,

In the Control Panel, Database, Cache area, what does Target Size refer to? Number of pages? Kilobytes? What does it mean by "target"? What exactly is being cached? Output from methods? The method content themselves? What is the difference between this and ZCache?

In this context 'cache' is the in-memory cache of Persistent objects (most objects in Zope are persistent, for example, just about everything you can add or manage in Zope is persisent). Obviously, it's not very good performance to read and write all objects to and from the database everytime you use them. Therefore, there is a cache to speed this up. The 'target' is the number of objects in the cache. Note that this is not a very hard limit, ie, if you set it to 10, it will let you load 10 tiny objects or 10 huge ones. Or 10 of mixed size. Experimenting this this value and watching how much memory Zope consumes is a good exercise in performance tuning. Note that there is NO magic value here, you have to play with it. Keep in mind that the default is very conservative, you can definatly start playing with it in the up direction (unless your running on a 386 with 16MB of RAM...). -Michel