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

AggregateExpression

AggregateFunction

AggregateMode

ApproxCountDistinctForIntervals

ApproximatePercentile

Max

Min

Sum

TypedImperativeAggregate

UnevaluableBooleanAggBase

V2Aggregator

VariancePop

VarianceSamp

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

PartialMerge

case object PartialMerge extends AggregateMode with scala.Product with Serializable

An AggregateFunction with PartialMerge mode is used to merge aggregation buffers containing intermediate results for this function. This function updates the given aggregation buffer by merging multiple aggregation buffers. When it has processed all input rows, the aggregation buffer is returned.

Linear Supertypes

Serializable, scala.Product, Equals, AggregateMode, AnyRef, Any

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final def !=(arg0: Any): Boolean
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final def ##: Int
Definition Classes
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Definition Classes
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final def asInstanceOf[T0]: T0
Definition Classes
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def clone(): AnyRef
Attributes
protected[lang]
Definition Classes
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final def eq(arg0: AnyRef): Boolean
Definition Classes
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def equals(arg0: AnyRef): Boolean
Definition Classes
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def finalize(): Unit
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final def getClass(): Class[_ <: AnyRef]
Definition Classes
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final def isInstanceOf[T0]: Boolean
Definition Classes
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final def ne(arg0: AnyRef): Boolean
Definition Classes
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final def notify(): Unit
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final def notifyAll(): Unit
Definition Classes
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@native()
def productElementName(n: Int): String
Definition Classes
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def productElementNames: Iterator[String]
Definition Classes
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final def synchronized[T0](arg0: => T0): T0
Definition Classes
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final def wait(): Unit
Definition Classes
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@throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long, arg1: Int): Unit
Definition Classes
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@throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long): Unit
Definition Classes
AnyRef
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@throws(classOf[java.lang.InterruptedException]) @native()

Packages

Standard Expressions

Named Expressions

Evaluation

PartialMerge

case object PartialMerge extends AggregateMode with scala.Product with Serializable

Value Members

Inherited from Serializable

Inherited from scala.Product

Inherited from Equals

Inherited from AggregateMode

Inherited from AnyRef

Inherited from Any

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Packages

Standard Expressions

Named Expressions

Evaluation

PartialMerge

case object PartialMerge extends AggregateMode with scala.Product with Serializable

Value Members

Inherited from Serializable

Inherited from scala.Product

Inherited from Equals

Inherited from AggregateMode

Inherited from AnyRef

Inherited from Any

Ungrouped

PartialMerge