Item caches hold the values of repository items, indexed by repository IDs. Item caching can be explicitly enabled for each item descriptor. Even if caching is explicitly disabled, item caching occurs within the scope of each transaction (see Disabling Caching).

An item cache entry is invalidated when that item is updated. The scope of an entry’s invalidation depends on its caching mode. For example, when an item is changed under simple caching mode, only the local cache entry is invalidated; other Oracle ATG Web Commerce instances are not notified. Oracle ATG Web Commerce provides several different Distributed Caching Modes to invalidate items across multiple instances.