-----Original Message----- From: David Kankiewicz [mailto:kankie@thegrid.net] Sent: Friday, November 19, 1999 12:50 AM To: Zope-dev@zope.org Subject: [Zope-dev] Max objects before ZCatalog?

What is the magic number for performance? Between the individual lookup, doing a 'large catalog' ZCatalog search, and creating many ZCatalogs.

'large' here is a big number. ZCatalog stores it's index information in BTrees. Without getting into too much theory or insulting anyones intelligence, a BTree is a tree like data structure. When doing a 'search' you start at the top and work your way down the tree, comparing your search value to the value of each node in the tree. If you had on the order of a million objects, you would only make on the order of 10-20 or so comparisons. This is very fast and scales quite well.

I'm accessing a few variable (~ 2-8) in 20-5000 (~max) subobjects and testing them against the current objects variables. The design is for something that most scale and can easily to be changed (I have this half done).

I don't really understand what your saying here. But if you have 5000 cataloged objects, max, then you're well below flexing catalog. -Michel