Object

mimir.optimizer.expression

PullUpBranches

Related Doc: package expression

Permalink

object PullUpBranches extends TopDownExpressionOptimizerRule

Optimization that moves conditionals higher in the expression tree.

For example: X > (IF Y = 2 THEN 5 ELSE 3) becomes: IF Y = 2 THEN X > 5 ELSE X > 3 which another rewrite turns into: ((Y = 2) AND (X > 5)) OR ((Y = 2) AND (X > 3))

This is analogous to inlining in imperative languages. The main perk is that it exposes new opportunities for expression evaluation, particularly related to simplification of expressions. The drawback is that it can create more complex expressions, since the non-conditional side needs to be duplicated.

This is particularly bad for conditionals, since (1) they have three separate subtrees that get cloned, and (2) they're already hard to optimize around. As a resut, we only apply this optimization to expressions where the LHS or RHS is a non-conditional

Linear Supertypes
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. PullUpBranches
  2. TopDownExpressionOptimizerRule
  3. ExpressionOptimizerRule
  4. AnyRef
  5. Any
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. All

Value Members

  1. final def !=(arg0: Any): Boolean

    Permalink
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int

    Permalink
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean

    Permalink
    Definition Classes
    AnyRef → Any
  4. def apply(e: Expression): Expression

    Permalink
  5. def applyOne(e: Expression): Expression

    Permalink
  6. final def asInstanceOf[T0]: T0

    Permalink
    Definition Classes
    Any
  7. def clone(): AnyRef

    Permalink
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  8. def containsConditional(e: Expression): Boolean

    Permalink
  9. final def eq(arg0: AnyRef): Boolean

    Permalink
    Definition Classes
    AnyRef
  10. def equals(arg0: Any): Boolean

    Permalink
    Definition Classes
    AnyRef → Any
  11. def finalize(): Unit

    Permalink
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  12. final def getClass(): Class[_]

    Permalink
    Definition Classes
    AnyRef → Any
  13. def hashCode(): Int

    Permalink
    Definition Classes
    AnyRef → Any
  14. final def isInstanceOf[T0]: Boolean

    Permalink
    Definition Classes
    Any
  15. final def ne(arg0: AnyRef): Boolean

    Permalink
    Definition Classes
    AnyRef
  16. final def notify(): Unit

    Permalink
    Definition Classes
    AnyRef
  17. final def notifyAll(): Unit

    Permalink
    Definition Classes
    AnyRef
  18. final def synchronized[T0](arg0: ⇒ T0): T0

    Permalink
    Definition Classes
    AnyRef
  19. def toString(): String

    Permalink
    Definition Classes
    AnyRef → Any
  20. final def wait(): Unit

    Permalink
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  21. final def wait(arg0: Long, arg1: Int): Unit

    Permalink
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  22. final def wait(arg0: Long): Unit

    Permalink
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Inherited from ExpressionOptimizerRule

Inherited from AnyRef

Inherited from Any

Ungrouped