Returns true if expr can be evaluated using only the output of plan.
Returns true if expr can be evaluated using only the output of plan. This method
can be used to determine when it is acceptable to move expression evaluation within a query
plan.
For example consider a join between two relations R(a, b) and S(c, d).
- canEvaluate(EqualTo(a,b), R) returns true
- canEvaluate(EqualTo(a,c), R) returns false
- canEvaluate(Literal(1), R) returns true as literals CAN be evaluated on any plan
Returns true iff expr could be evaluated as a condition within join.
Returns true iff expr could be evaluated as a condition within join.
Name for this rule, automatically inferred based on class name.
Name for this rule, automatically inferred based on class name.
Pushes down Filter operators where the
conditioncan be evaluated using only the attributes of the left or right side of a join. Other Filter conditions are moved into theconditionof the Join.And also pushes down the join filter, where the
conditioncan be evaluated using only the attributes of the left or right side of sub query when applicable.Check https://cwiki.apache.org/confluence/display/Hive/OuterJoinBehavior for more details