Packages

o

org.apache.spark.sql.catalyst.optimizer

UnwrapCastInBinaryComparison

object UnwrapCastInBinaryComparison extends Rule[LogicalPlan]

Unwrap casts in binary comparison operations with patterns like following:

BinaryComparison(Cast(fromExp, toType), Literal(value, toType)) or BinaryComparison(Literal(value, toType), Cast(fromExp, toType))

This rule optimizes expressions with the above pattern by either replacing the cast with simpler constructs, or moving the cast from the expression side to the literal side, which enables them to be optimized away later and pushed down to data sources.

Currently this only handles cases where: 1). fromType (of fromExp) and toType are of numeric types (i.e., short, int, float, decimal, etc) 2). fromType can be safely coerced to toType without precision loss (e.g., short to int, int to long, but not long to int)

If the above conditions are satisfied, the rule checks to see if the literal value is within range (min, max), where min and max are the minimum and maximum value of fromType, respectively. If this is true then it means we may safely cast value to fromType and thus able to move the cast to the literal side. That is:

cast(fromExp, toType) op value ==> fromExp op cast(value, fromType)

Note there are some exceptions to the above: if casting from value to fromType causes rounding up or down, the above conversion will no longer be valid. Instead, the rule does the following:

if casting value to fromType causes rounding up:

  • cast(fromExp, toType) > value ==> fromExp >= cast(value, fromType)
  • cast(fromExp, toType) >= value ==> fromExp >= cast(value, fromType)
  • cast(fromExp, toType) === value ==> if(isnull(fromExp), null, false)
  • cast(fromExp, toType) <=> value ==> false (if fromExp is deterministic)
  • cast(fromExp, toType) <= value ==> fromExp < cast(value, fromType)
  • cast(fromExp, toType) < value ==> fromExp < cast(value, fromType)

Similarly for the case when casting value to fromType causes rounding down.

If the value is not within range (min, max), the rule breaks the scenario into different cases and try to replace each with simpler constructs.

if value > max, the cases are of following:

  • cast(fromExp, toType) > value ==> if(isnull(fromExp), null, false)
  • cast(fromExp, toType) >= value ==> if(isnull(fromExp), null, false)
  • cast(fromExp, toType) === value ==> if(isnull(fromExp), null, false)
  • cast(fromExp, toType) <=> value ==> false (if fromExp is deterministic)
  • cast(fromExp, toType) <= value ==> if(isnull(fromExp), null, true)
  • cast(fromExp, toType) < value ==> if(isnull(fromExp), null, true)

if value == max, the cases are of following:

  • cast(fromExp, toType) > value ==> if(isnull(fromExp), null, false)
  • cast(fromExp, toType) >= value ==> fromExp == max
  • cast(fromExp, toType) === value ==> fromExp == max
  • cast(fromExp, toType) <=> value ==> fromExp <=> max
  • cast(fromExp, toType) <= value ==> if(isnull(fromExp), null, true)
  • cast(fromExp, toType) < value ==> fromExp =!= max

Similarly for the cases when value == min and value < min.

Further, the above if(isnull(fromExp), null, false) is represented using conjunction and(isnull(fromExp), null), to enable further optimization and filter pushdown to data sources. Similarly, if(isnull(fromExp), null, true) is represented with or(isnotnull(fromExp), null).

Linear Supertypes
Rule[LogicalPlan], Logging, SQLConfHelper, AnyRef, Any
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. UnwrapCastInBinaryComparison
  2. Rule
  3. Logging
  4. SQLConfHelper
  5. AnyRef
  6. Any
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. All

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. def apply(plan: LogicalPlan): LogicalPlan
    Definition Classes
    UnwrapCastInBinaryComparison → Rule
  5. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  6. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  7. def conf: SQLConf

    The active config object within the current scope.

    The active config object within the current scope. See SQLConf.get for more information.

    Definition Classes
    SQLConfHelper
  8. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  9. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  10. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  11. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  12. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  13. def initializeLogIfNecessary(isInterpreter: Boolean, silent: Boolean): Boolean
    Attributes
    protected
    Definition Classes
    Logging
  14. def initializeLogIfNecessary(isInterpreter: Boolean): Unit
    Attributes
    protected
    Definition Classes
    Logging
  15. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  16. def isTraceEnabled(): Boolean
    Attributes
    protected
    Definition Classes
    Logging
  17. def log: Logger
    Attributes
    protected
    Definition Classes
    Logging
  18. def logDebug(msg: ⇒ String, throwable: Throwable): Unit
    Attributes
    protected
    Definition Classes
    Logging
  19. def logDebug(msg: ⇒ String): Unit
    Attributes
    protected
    Definition Classes
    Logging
  20. def logError(msg: ⇒ String, throwable: Throwable): Unit
    Attributes
    protected
    Definition Classes
    Logging
  21. def logError(msg: ⇒ String): Unit
    Attributes
    protected
    Definition Classes
    Logging
  22. def logInfo(msg: ⇒ String, throwable: Throwable): Unit
    Attributes
    protected
    Definition Classes
    Logging
  23. def logInfo(msg: ⇒ String): Unit
    Attributes
    protected
    Definition Classes
    Logging
  24. def logName: String
    Attributes
    protected
    Definition Classes
    Logging
  25. def logTrace(msg: ⇒ String, throwable: Throwable): Unit
    Attributes
    protected
    Definition Classes
    Logging
  26. def logTrace(msg: ⇒ String): Unit
    Attributes
    protected
    Definition Classes
    Logging
  27. def logWarning(msg: ⇒ String, throwable: Throwable): Unit
    Attributes
    protected
    Definition Classes
    Logging
  28. def logWarning(msg: ⇒ String): Unit
    Attributes
    protected
    Definition Classes
    Logging
  29. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  30. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  31. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  32. val ruleName: String

    Name for this rule, automatically inferred based on class name.

    Name for this rule, automatically inferred based on class name.

    Definition Classes
    Rule
  33. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  34. def toString(): String
    Definition Classes
    AnyRef → Any
  35. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  36. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  37. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()

Inherited from Rule[LogicalPlan]

Inherited from Logging

Inherited from SQLConfHelper

Inherited from AnyRef

Inherited from Any

Ungrouped