ISWC 2008: Some Questions - Inference: Is it always forward chaining?(About) Once the working set is no longer in memory, response times jump disproportionately. Also, if the data changes or is retracted or is unreliable, one can end up doing a lot of extra work with materialization. Consider the effect of one malicious sameAs statement. This can lead to a lot of effects that are hard to retract. On the other hand, if running in memory with static data..., the queries run some 20% faster if entailment subclasses and sub-properties are materialized rather than done at run time.