org.apache.spark.sql.catalyst.optimizer
Attempts to eliminate the reading of unneeded columns from the query plan.
Since adding Project before Filter conflicts with PushPredicatesThroughProject, this rule will remove the Project p2 in the following pattern:
p1 @ Project(_, Filter(_, p2 @ Project(_, child))) if p2.outputSet.subsetOf(p2.inputSet)
p2 is usually inserted by this rule and useless, p1 could prune the columns anyway.
Name for this rule, automatically inferred based on class name.
Attempts to eliminate the reading of unneeded columns from the query plan.
Since adding Project before Filter conflicts with PushPredicatesThroughProject, this rule will remove the Project p2 in the following pattern:
p1 @ Project(_, Filter(_, p2 @ Project(_, child))) if p2.outputSet.subsetOf(p2.inputSet)
p2 is usually inserted by this rule and useless, p1 could prune the columns anyway.