io.prestosql.sql.planner.optimizations

Class PruneUnreferencedOutputs

java.lang.Object

io.prestosql.sql.planner.optimizations.PruneUnreferencedOutputs

All Implemented Interfaces:

PlanOptimizer

public class PruneUnreferencedOutputs
extends Object
implements PlanOptimizer

Removes all computation that does is not referenced transitively from the root of the plan

E.g.,

Output[$0] -> Project[$0 := $1 + $2, $3 = $4 / $5] -> ...

gets rewritten as

Output[$0] -> Project[$0 := $1 + $2] -> ...

Constructor Summary

Constructors

Constructor and Description
PruneUnreferencedOutputs()

Method Summary

Modifier and Type	Method and Description
PlanNode	optimize(PlanNode plan, Session session, TypeProvider types, SymbolAllocator symbolAllocator, PlanNodeIdAllocator idAllocator, WarningCollector warningCollector)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PruneUnreferencedOutputs

public PruneUnreferencedOutputs()

Method Detail

optimize

public PlanNode optimize(PlanNode plan,
                         Session session,
                         TypeProvider types,
                         SymbolAllocator symbolAllocator,
                         PlanNodeIdAllocator idAllocator,
                         WarningCollector warningCollector)

Specified by:

optimize in interface PlanOptimizer