Rule cache

The rule cache, also referred to as the database cache or system cache, contains recently found and non-found rules that are used to improve the performance of the engine, especially during rule resolution searches. The system adds to the cache any rule that is read three or more times, however, for some rule types, a higher limit applies.

Note: Instances of most concrete classes other than those derived from the Rule- base class are not cached in the rule cache.

In a clustered system, a rule recently updated by a user on one node can also be present (and stale) in the rule cache of another node. During system pulse processing, the Pega-RULES agent on each node clears such stale rules from the rule cache.