Package that contains the basic data structure used by Felix.
There are two groups of data structures:
- Structures used in Felix's execution plan.
This includes execution plans, operator buckets, and operators.
An execution plan consists of a list of operator buckets.
Each operator bucket is made up of one or more operators which
may be data movement operators (DMOs) or statistical operators (COREF, CRF, LR, TUFFY).
- Structures used for Felix's input.
This includes clauses, predicates, and queries.
These structures are extended from the corresponding structures in Tuffy.