Every component in Ab initio has a memory of 7MB (anybody correct me if I'm wrong) except a few components like In-Memory components such as join, Rollup, Scan, join with DB etc., which uses an additional memory called Max-Core. This parameter is only available if your data is not explicitly sorted and your component also needs to sort the data besides the processing.This additional memory is also used to store the temporary results.There is no specific fixed value for the max core and each in-memory component has a default max core value like 10MB for sort and 64 MB for join component etc.,