Class

org.apache.spark.sql.catalyst.expressions.aggregate

Skewness

Related Doc: package aggregate

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case class Skewness(child: Expression, mutableAggBufferOffset: Int = 0, inputAggBufferOffset: Int = 0) extends CentralMomentAgg with Product with Serializable

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Inherited
  1. Skewness
  2. CentralMomentAgg
  3. Serializable
  4. Serializable
  5. ImperativeAggregate
  6. AggregateFunction
  7. ImplicitCastInputTypes
  8. ExpectsInputTypes
  9. Expression
  10. TreeNode
  11. Product
  12. Equals
  13. AnyRef
  14. Any
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Visibility
  1. Public
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Instance Constructors

  1. new Skewness(child: Expression)

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  2. new Skewness(child: Expression, mutableAggBufferOffset: Int = 0, inputAggBufferOffset: Int = 0)

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Value Members

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

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

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

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    Definition Classes
    AnyRef → Any
  4. val aggBufferAttributes: Seq[AttributeReference]

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    Attributes of fields in aggBufferSchema.

    Attributes of fields in aggBufferSchema.

    Definition Classes
    CentralMomentAggAggregateFunction
  5. def aggBufferSchema: StructType

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    The schema of the aggregation buffer.

    The schema of the aggregation buffer.

    Definition Classes
    CentralMomentAggAggregateFunction
  6. def apply(number: Int): Expression

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    Returns the tree node at the specified number.

    Returns the tree node at the specified number. Numbers for each node can be found in the numberedTreeString.

    Definition Classes
    TreeNode
  7. def argString: String

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    Returns a string representing the arguments to this node, minus any children

    Returns a string representing the arguments to this node, minus any children

    Definition Classes
    TreeNode
  8. def asCode: String

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    Returns a 'scala code' representation of this TreeNode and its children.

    Returns a 'scala code' representation of this TreeNode and its children. Intended for use when debugging where the prettier toString function is obfuscating the actual structure. In the case of 'pure' TreeNodes that only contain primitives and other TreeNodes, the result can be pasted in the REPL to build an equivalent Tree.

    Definition Classes
    TreeNode
  9. final def asInstanceOf[T0]: T0

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    Definition Classes
    Any
  10. def checkInputDataTypes(): TypeCheckResult

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    Checks the input data types, returns TypeCheckResult.success if it's valid, or returns a TypeCheckResult with an error message if invalid.

    Checks the input data types, returns TypeCheckResult.success if it's valid, or returns a TypeCheckResult with an error message if invalid. Note: it's not valid to call this method until childrenResolved == true.

    Definition Classes
    CentralMomentAggExpectsInputTypesExpression
  11. val child: Expression

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  12. def children: Seq[Expression]

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    Returns a Seq of the children of this node.

    Returns a Seq of the children of this node. Children should not change. Immutability required for containsChild optimization

    Definition Classes
    CentralMomentAggTreeNode
  13. def childrenResolved: Boolean

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    Returns true if all the children of this expression have been resolved to a specific schema and false if any still contains any unresolved placeholders.

    Returns true if all the children of this expression have been resolved to a specific schema and false if any still contains any unresolved placeholders.

    Definition Classes
    Expression
  14. def clone(): AnyRef

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    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  15. def collect[B](pf: PartialFunction[Expression, B]): Seq[B]

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    Returns a Seq containing the result of applying a partial function to all elements in this tree on which the function is defined.

    Returns a Seq containing the result of applying a partial function to all elements in this tree on which the function is defined.

    Definition Classes
    TreeNode
  16. def collectFirst[B](pf: PartialFunction[Expression, B]): Option[B]

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    Finds and returns the first TreeNode of the tree for which the given partial function is defined (pre-order), and applies the partial function to it.

    Finds and returns the first TreeNode of the tree for which the given partial function is defined (pre-order), and applies the partial function to it.

    Definition Classes
    TreeNode
  17. lazy val containsChild: Set[TreeNode[_]]

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    Definition Classes
    TreeNode
  18. def dataType: DataType

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    Returns the DataType of the result of evaluating this expression.

    Returns the DataType of the result of evaluating this expression. It is invalid to query the dataType of an unresolved expression (i.e., when resolved == false).

    Definition Classes
    CentralMomentAggExpression
  19. def defaultResult: Option[Literal]

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    Result of the aggregate function when the input is empty.

    Result of the aggregate function when the input is empty. This is currently only used for the proper rewriting of distinct aggregate functions.

    Definition Classes
    AggregateFunction
  20. def deterministic: Boolean

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    Returns true when the current expression always return the same result for fixed inputs from children.

    Returns true when the current expression always return the same result for fixed inputs from children.

    Note that this means that an expression should be considered as non-deterministic if: - if it relies on some mutable internal state, or - if it relies on some implicit input that is not part of the children expression list. - if it has non-deterministic child or children.

    An example would be SparkPartitionID that relies on the partition id returned by TaskContext. By default leaf expressions are deterministic as Nil.forall(_.deterministic) returns true.

    Definition Classes
    Expression
  21. final def eq(arg0: AnyRef): Boolean

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    Definition Classes
    AnyRef
  22. final def eval(buffer: InternalRow): Any

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    Returns the result of evaluating this expression on a given input Row

    Returns the result of evaluating this expression on a given input Row

    Definition Classes
    CentralMomentAggExpression
  23. def fastEquals(other: TreeNode[_]): Boolean

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    Faster version of equality which short-circuits when two treeNodes are the same instance.

    Faster version of equality which short-circuits when two treeNodes are the same instance. We don't just override Object.equals, as doing so prevents the scala compiler from generating case class equals methods

    Definition Classes
    TreeNode
  24. def finalize(): Unit

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    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  25. def find(f: (Expression) ⇒ Boolean): Option[Expression]

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    Find the first TreeNode that satisfies the condition specified by f.

    Find the first TreeNode that satisfies the condition specified by f. The condition is recursively applied to this node and all of its children (pre-order).

    Definition Classes
    TreeNode
  26. def flatMap[A](f: (Expression) ⇒ TraversableOnce[A]): Seq[A]

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    Returns a Seq by applying a function to all nodes in this tree and using the elements of the resulting collections.

    Returns a Seq by applying a function to all nodes in this tree and using the elements of the resulting collections.

    Definition Classes
    TreeNode
  27. final def foldable: Boolean

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    An aggregate function is not foldable.

    An aggregate function is not foldable.

    Definition Classes
    AggregateFunctionExpression
  28. def foreach(f: (Expression) ⇒ Unit): Unit

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    Runs the given function on this node and then recursively on children.

    Runs the given function on this node and then recursively on children.

    f

    the function to be applied to each node in the tree.

    Definition Classes
    TreeNode
  29. def foreachUp(f: (Expression) ⇒ Unit): Unit

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    Runs the given function recursively on children then on this node.

    Runs the given function recursively on children then on this node.

    f

    the function to be applied to each node in the tree.

    Definition Classes
    TreeNode
  30. def gen(ctx: CodeGenContext): GeneratedExpressionCode

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    Returns an GeneratedExpressionCode, which contains Java source code that can be used to generate the result of evaluating the expression on an input row.

    Returns an GeneratedExpressionCode, which contains Java source code that can be used to generate the result of evaluating the expression on an input row.

    ctx

    a CodeGenContext

    returns

    GeneratedExpressionCode

    Definition Classes
    Expression
  31. def genCode(ctx: CodeGenContext, ev: GeneratedExpressionCode): String

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    Returns Java source code that can be compiled to evaluate this expression.

    Returns Java source code that can be compiled to evaluate this expression. The default behavior is to call the eval method of the expression. Concrete expression implementations should override this to do actual code generation.

    ctx

    a CodeGenContext

    ev

    an GeneratedExpressionCode with unique terms.

    returns

    Java source code

    Attributes
    protected
    Definition Classes
    AggregateFunctionExpression
  32. def generateTreeString(depth: Int, lastChildren: Seq[Boolean], builder: StringBuilder): StringBuilder

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    Appends the string represent of this node and its children to the given StringBuilder.

    Appends the string represent of this node and its children to the given StringBuilder.

    The i-th element in lastChildren indicates whether the ancestor of the current node at depth i + 1 is the last child of its own parent node. The depth of the root node is 0, and lastChildren for the root node should be empty.

    Attributes
    protected
    Definition Classes
    TreeNode
  33. final def getClass(): Class[_]

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    Definition Classes
    AnyRef → Any
  34. def getNodeNumbered(number: trees.MutableInt): Expression

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    Attributes
    protected
    Definition Classes
    TreeNode
  35. def getStatistic(n: Double, mean: Double, moments: Array[Double]): Any

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    Compute aggregate statistic from sufficient moments.

    Compute aggregate statistic from sufficient moments.

    Definition Classes
    SkewnessCentralMomentAgg
  36. def initialize(buffer: MutableRow): Unit

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    Initialize all moments to zero.

    Initialize all moments to zero.

    Definition Classes
    CentralMomentAggImperativeAggregate
  37. val inputAggBufferAttributes: Seq[AttributeReference]

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    Attributes of fields in input aggregation buffers (immutable aggregation buffers that are merged with mutable aggregation buffers in the merge() function or merge expressions).

    Attributes of fields in input aggregation buffers (immutable aggregation buffers that are merged with mutable aggregation buffers in the merge() function or merge expressions). These attributes are created automatically by cloning the aggBufferAttributes.

    Definition Classes
    CentralMomentAggAggregateFunction
  38. val inputAggBufferOffset: Int

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    The offset of this function's start buffer value in the underlying shared input aggregation buffer.

    The offset of this function's start buffer value in the underlying shared input aggregation buffer. An input aggregation buffer is used when we merge two aggregation buffers together in the update() function and is immutable (we merge an input aggregation buffer and a mutable aggregation buffer and then store the new buffer values to the mutable aggregation buffer).

    An input aggregation buffer may contain extra fields, such as grouping keys, at its start, so mutableAggBufferOffset and inputAggBufferOffset are often different.

    For example, say we have a grouping expression, key, and two aggregate functions, avg(x) and avg(y). In the shared input aggregation buffer, the position of the first buffer value of avg(x) will be 1 and the position of the first buffer value of avg(y) will be 3 (position 0 is used for the value of key):

    avg(x) inputAggBufferOffset = 1 | v +--------+--------+--------+--------+--------+ | key | sum1 | count1 | sum2 | count2 | +--------+--------+--------+--------+--------+ ^ | avg(y) inputAggBufferOffset = 3

    Definition Classes
    SkewnessImperativeAggregate
  39. def inputTypes: Seq[AbstractDataType]

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    Expected input types from child expressions.

    Expected input types from child expressions. The i-th position in the returned seq indicates the type requirement for the i-th child.

    The possible values at each position are: 1. a specific data type, e.g. LongType, StringType. 2. a non-leaf abstract data type, e.g. NumericType, IntegralType, FractionalType.

    Definition Classes
    CentralMomentAggExpectsInputTypes
  40. final def isInstanceOf[T0]: Boolean

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    Definition Classes
    Any
  41. def jsonFields: List[JField]

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    Attributes
    protected
    Definition Classes
    TreeNode
  42. def makeCopy(newArgs: Array[AnyRef]): Expression

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    Creates a copy of this type of tree node after a transformation.

    Creates a copy of this type of tree node after a transformation. Must be overridden by child classes that have constructor arguments that are not present in the productIterator.

    newArgs

    the new product arguments.

    Definition Classes
    TreeNode
  43. def map[A](f: (Expression) ⇒ A): Seq[A]

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    Returns a Seq containing the result of applying the given function to each node in this tree in a preorder traversal.

    Returns a Seq containing the result of applying the given function to each node in this tree in a preorder traversal.

    f

    the function to be applied.

    Definition Classes
    TreeNode
  44. def mapChildren(f: (Expression) ⇒ Expression): Expression

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    Returns a copy of this node where f has been applied to all the nodes children.

    Returns a copy of this node where f has been applied to all the nodes children.

    Definition Classes
    TreeNode
  45. def merge(buffer1: MutableRow, buffer2: InternalRow): Unit

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    Merge two central moment buffers.

    Merge two central moment buffers.

    Definition Classes
    CentralMomentAggImperativeAggregate
  46. val momentOrder: Int

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    The central moment order to be computed.

    The central moment order to be computed.

    Attributes
    protected
    Definition Classes
    SkewnessCentralMomentAgg
  47. val mutableAggBufferOffset: Int

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    The offset of this function's first buffer value in the underlying shared mutable aggregation buffer.

    The offset of this function's first buffer value in the underlying shared mutable aggregation buffer.

    For example, we have two aggregate functions avg(x) and avg(y), which share the same aggregation buffer. In this shared buffer, the position of the first buffer value of avg(x) will be 0 and the position of the first buffer value of avg(y) will be 2:

    avg(x) mutableAggBufferOffset = 0 | v +--------+--------+--------+--------+ | sum1 | count1 | sum2 | count2 | +--------+--------+--------+--------+ ^ | avg(y) mutableAggBufferOffset = 2

    Definition Classes
    SkewnessImperativeAggregate
  48. final def ne(arg0: AnyRef): Boolean

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    Definition Classes
    AnyRef
  49. def nodeName: String

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    Returns the name of this type of TreeNode.

    Returns the name of this type of TreeNode. Defaults to the class name.

    Definition Classes
    TreeNode
  50. final def notify(): Unit

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    Definition Classes
    AnyRef
  51. final def notifyAll(): Unit

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    Definition Classes
    AnyRef
  52. def nullable: Boolean

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    Definition Classes
    CentralMomentAggExpression
  53. def numberedTreeString: String

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    Returns a string representation of the nodes in this tree, where each operator is numbered.

    Returns a string representation of the nodes in this tree, where each operator is numbered. The numbers can be used with apply to easily access specific subtrees.

    Definition Classes
    TreeNode
  54. val origin: Origin

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    Definition Classes
    TreeNode
  55. def otherCopyArgs: Seq[AnyRef]

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    Args to the constructor that should be copied, but not transformed.

    Args to the constructor that should be copied, but not transformed. These are appended to the transformed args automatically by makeCopy

    Attributes
    protected
    Definition Classes
    TreeNode
  56. def prettyJson: String

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    Definition Classes
    TreeNode
  57. def prettyName: String

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    Returns a user-facing string representation of this expression's name.

    Returns a user-facing string representation of this expression's name. This should usually match the name of the function in SQL.

    Definition Classes
    SkewnessExpression
  58. def prettyString: String

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    Returns a user-facing string representation of this expression, i.e.

    Returns a user-facing string representation of this expression, i.e. does not have developer centric debugging information like the expression id.

    Definition Classes
    Expression
  59. def references: AttributeSet

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    Definition Classes
    Expression
  60. lazy val resolved: Boolean

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    Returns true if this expression and all its children have been resolved to a specific schema and input data types checking passed, and false if it still contains any unresolved placeholders or has data types mismatch.

    Returns true if this expression and all its children have been resolved to a specific schema and input data types checking passed, and false if it still contains any unresolved placeholders or has data types mismatch. Implementations of expressions should override this if the resolution of this type of expression involves more than just the resolution of its children and type checking.

    Definition Classes
    Expression
  61. def semanticEquals(other: Expression): Boolean

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    Returns true when two expressions will always compute the same result, even if they differ cosmetically (i.e.

    Returns true when two expressions will always compute the same result, even if they differ cosmetically (i.e. capitalization of names in attributes may be different).

    Definition Classes
    Expression
  62. def semanticHash(): Int

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    Returns the hash for this expression.

    Returns the hash for this expression. Expressions that compute the same result, even if they differ cosmetically should return the same hash.

    Definition Classes
    Expression
  63. def simpleString: String

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    String representation of this node without any children

    String representation of this node without any children

    Definition Classes
    ExpressionTreeNode
  64. def stringArgs: Iterator[Any]

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    The arguments that should be included in the arg string.

    The arguments that should be included in the arg string. Defaults to the productIterator.

    Attributes
    protected
    Definition Classes
    TreeNode
  65. def supportsPartial: Boolean

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    Indicates if this function supports partial aggregation.

    Indicates if this function supports partial aggregation. Currently Hive UDAF is the only one that doesn't support partial aggregation.

    Definition Classes
    AggregateFunction
  66. final def synchronized[T0](arg0: ⇒ T0): T0

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    Definition Classes
    AnyRef
  67. def toAggregateExpression(isDistinct: Boolean): AggregateExpression

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    Wraps this AggregateFunction in an AggregateExpression and set isDistinct field of the AggregateExpression to the given value because AggregateExpression is the container of an AggregateFunction, aggregation mode, and the flag indicating if this aggregation is distinct aggregation or not.

    Wraps this AggregateFunction in an AggregateExpression and set isDistinct field of the AggregateExpression to the given value because AggregateExpression is the container of an AggregateFunction, aggregation mode, and the flag indicating if this aggregation is distinct aggregation or not. An AggregateFunction should not be used without being wrapped in an AggregateExpression.

    Definition Classes
    AggregateFunction
  68. def toAggregateExpression(): AggregateExpression

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    Wraps this AggregateFunction in an AggregateExpression because AggregateExpression is the container of an AggregateFunction, aggregation mode, and the flag indicating if this aggregation is distinct aggregation or not.

    Wraps this AggregateFunction in an AggregateExpression because AggregateExpression is the container of an AggregateFunction, aggregation mode, and the flag indicating if this aggregation is distinct aggregation or not. An AggregateFunction should not be used without being wrapped in an AggregateExpression.

    Definition Classes
    AggregateFunction
  69. def toJSON: String

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    Definition Classes
    TreeNode
  70. def toString(): String

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    Definition Classes
    ExpressionTreeNode → AnyRef → Any
  71. def transform(rule: PartialFunction[Expression, Expression]): Expression

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    Returns a copy of this node where rule has been recursively applied to the tree.

    Returns a copy of this node where rule has been recursively applied to the tree. When rule does not apply to a given node it is left unchanged. Users should not expect a specific directionality. If a specific directionality is needed, transformDown or transformUp should be used.

    rule

    the function use to transform this nodes children

    Definition Classes
    TreeNode
  72. def transformChildren(rule: PartialFunction[Expression, Expression], nextOperation: (Expression, PartialFunction[Expression, Expression]) ⇒ Expression): Expression

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    Returns a copy of this node where rule has been recursively applied to all the children of this node.

    Returns a copy of this node where rule has been recursively applied to all the children of this node. When rule does not apply to a given node it is left unchanged.

    rule

    the function used to transform this nodes children

    Attributes
    protected
    Definition Classes
    TreeNode
  73. def transformDown(rule: PartialFunction[Expression, Expression]): Expression

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    Returns a copy of this node where rule has been recursively applied to it and all of its children (pre-order).

    Returns a copy of this node where rule has been recursively applied to it and all of its children (pre-order). When rule does not apply to a given node it is left unchanged.

    rule

    the function used to transform this nodes children

    Definition Classes
    TreeNode
  74. def transformUp(rule: PartialFunction[Expression, Expression]): Expression

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    Returns a copy of this node where rule has been recursively applied first to all of its children and then itself (post-order).

    Returns a copy of this node where rule has been recursively applied first to all of its children and then itself (post-order). When rule does not apply to a given node, it is left unchanged.

    rule

    the function use to transform this nodes children

    Definition Classes
    TreeNode
  75. def treeString: String

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    Returns a string representation of the nodes in this tree

    Returns a string representation of the nodes in this tree

    Definition Classes
    TreeNode
  76. def update(buffer: MutableRow, input: InternalRow): Unit

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    Update the central moments buffer.

    Update the central moments buffer.

    Definition Classes
    CentralMomentAggImperativeAggregate
  77. final def wait(): Unit

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

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

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  80. def withNewChildren(newChildren: Seq[Expression]): Expression

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    Returns a copy of this node with the children replaced.

    Returns a copy of this node with the children replaced. TODO: Validate somewhere (in debug mode?) that children are ordered correctly.

    Definition Classes
    TreeNode
  81. def withNewInputAggBufferOffset(newInputAggBufferOffset: Int): ImperativeAggregate

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    Returns a copy of this ImperativeAggregate with an updated mutableAggBufferOffset.

    Returns a copy of this ImperativeAggregate with an updated mutableAggBufferOffset. This new copy's attributes may have different ids than the original.

    Definition Classes
    SkewnessImperativeAggregate
  82. def withNewMutableAggBufferOffset(newMutableAggBufferOffset: Int): ImperativeAggregate

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    Returns a copy of this ImperativeAggregate with an updated mutableAggBufferOffset.

    Returns a copy of this ImperativeAggregate with an updated mutableAggBufferOffset. This new copy's attributes may have different ids than the original.

    Definition Classes
    SkewnessImperativeAggregate

Inherited from CentralMomentAgg

Inherited from Serializable

Inherited from Serializable

Inherited from ImperativeAggregate

Inherited from AggregateFunction

Inherited from ImplicitCastInputTypes

Inherited from ExpectsInputTypes

Inherited from Expression

Inherited from TreeNode[Expression]

Inherited from Product

Inherited from Equals

Inherited from AnyRef

Inherited from Any

Ungrouped