Heuristics Based Logical Query Optimizer

HeFQUIN uses a heuristics-based query optimizer for its logical plans. The relevant source code can be found in the se.liu.ida.hefquin.engine.queryproc.impl.loptimizer package and its sub-packages.

Heuristics that are currently implemented:

• CardinalityBasedJoinOrderingWithRequests
• FilterPushDown
• GreedyBasedReordering
• MergeRequests
• PullUpLtgOverJoin
• PullUpLtgOverUnion
• PushJoinUnderUnionWithRequests
• RemovePairsOfG2lAndL2g
• RemoveUnnecessaryL2gAndG2l
• UnionPullUp