Packages

  • package root
    Definition Classes
    root
  • package org
    Definition Classes
    root
  • package apache
    Definition Classes
    org
  • package spark
    Definition Classes
    apache
  • package sql
    Definition Classes
    spark
  • package catalyst

    Catalyst is a library for manipulating relational query plans.

    Catalyst is a library for manipulating relational query plans. All classes in catalyst are considered an internal API to Spark SQL and are subject to change between minor releases.

    Definition Classes
    sql
  • package expressions

    A set of classes that can be used to represent trees of relational expressions.

    A set of classes that can be used to represent trees of relational expressions. A key goal of the expression library is to hide the details of naming and scoping from developers who want to manipulate trees of relational operators. As such, the library defines a special type of expression, a NamedExpression in addition to the standard collection of expressions.

    Standard Expressions

    A library of standard expressions (e.g., Add, EqualTo), aggregates (e.g., SUM, COUNT), and other computations (e.g. UDFs). Each expression type is capable of determining its output schema as a function of its children's output schema.

    Named Expressions

    Some expression are named and thus can be referenced by later operators in the dataflow graph. The two types of named expressions are AttributeReferences and Aliases. AttributeReferences refer to attributes of the input tuple for a given operator and form the leaves of some expression trees. Aliases assign a name to intermediate computations. For example, in the SQL statement SELECT a+b AS c FROM ..., the expressions a and b would be represented by AttributeReferences and c would be represented by an Alias.

    During analysis, all named expressions are assigned a globally unique expression id, which can be used for equality comparisons. While the original names are kept around for debugging purposes, they should never be used to check if two attributes refer to the same value, as plan transformations can result in the introduction of naming ambiguity. For example, consider a plan that contains subqueries, both of which are reading from the same table. If an optimization removes the subqueries, scoping information would be destroyed, eliminating the ability to reason about which subquery produced a given attribute.

    Evaluation

    The result of expressions can be evaluated using the Expression.apply(Row) method.

    Definition Classes
    catalyst
  • package aggregate
    Definition Classes
    expressions
  • object ApproximatePercentile extends Serializable
    Definition Classes
    aggregate
  • PercentileDigest
  • PercentileDigestSerializer

class PercentileDigest extends AnyRef

PercentileDigest is a probabilistic data structure used for approximating percentiles with limited memory. PercentileDigest is backed by QuantileSummaries.

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  1. PercentileDigest
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Instance Constructors

  1. new PercentileDigest(relativeError: Double)
  2. new PercentileDigest(summaries: QuantileSummaries)

    summaries

    underlying probabilistic data structure QuantileSummaries.

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 add(value: Double): Unit

    Insert an observation value into the PercentileDigest data structure.

  5. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  6. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
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    Annotations
    @throws( ... ) @native()
  7. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  8. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  9. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  10. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  11. def getPercentiles(percentages: Array[Double]): Array[Double]

    Returns the approximate percentiles of all observation values at the given percentages.

    Returns the approximate percentiles of all observation values at the given percentages. A percentile is a watermark value below which a given percentage of observation values fall. For example, the following code returns the 25th, median, and 75th percentiles of all observation values:

    val Array(p25, median, p75) = percentileDigest.getPercentiles(Array(0.25, 0.5, 0.75))
  12. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  13. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  14. def merge(other: PercentileDigest): Unit

    In-place merges in another PercentileDigest.

  15. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  16. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  17. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  18. def quantileSummaries: QuantileSummaries

    Returns compressed object of QuantileSummaries

  19. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  20. def toString(): String
    Definition Classes
    AnyRef → Any
  21. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  22. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
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    @throws( ... )
  23. final def wait(arg0: Long): Unit
    Definition Classes
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    @throws( ... ) @native()

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