In an ATG Commerce application, caches for the product catalog repository should be large enough to accommodate the entire catalog—its categories, products and SKUs—or the data that is most frequently accessed. In general, a site can comfortably cache a catalog that contains up to 2 thousand categories, 10 thousand products, and 100 thousand SKUs.

In order to set cache sizes for /atg/commerce/order/OrderRepository, estimate the number of concurrent sessions, and the number of expected orders, items, and shipping groups. The following table provides some guidance on how to set cache sizes for various item descriptors:

Item descriptor

Typical site usage

Item cache size


500 concurrent user sessions



3 items per order (average)



2 shipping groups per order