ImperativeAggregate — Aggregate Function Expressions with Imperative Methods¶

ImperativeAggregate is the <> for aggregate functions that are expressed in terms of imperative <>, <>, and <> methods (that operate on Row-based aggregation buffers).

ImperativeAggregate is a Catalyst expression with CodegenFallback.

[[implementations]] .ImperativeAggregate's Direct Implementations [width="100%",cols="1,2",options="header"] |=== | Name | Description

=== [[contract]] ImperativeAggregate Contract

[source, scala]¶

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

abstract class ImperativeAggregate { def initialize(mutableAggBuffer: InternalRow): Unit val inputAggBufferOffset: Int def merge(mutableAggBuffer: InternalRow, inputAggBuffer: InternalRow): Unit val mutableAggBufferOffset: Int def update(mutableAggBuffer: InternalRow, inputRow: InternalRow): Unit def withNewInputAggBufferOffset(newInputAggBufferOffset: Int): ImperativeAggregate def withNewMutableAggBufferOffset(newMutableAggBufferOffset: Int): ImperativeAggregate }

.ImperativeAggregate Contract [cols="1,2",options="header",width="100%"] |=== | Method | Description

| [[initialize]] initialize a|

Used when:

• AggregateProcessor is initialized (for window aggregate functions)

• AggregationIterator, ObjectAggregationIterator, TungstenAggregationIterator (for aggregate functions)

| [[merge]] merge a|

Used when:

• AggregationIterator does generateProcessRow (for aggregate functions)

| [[update]] update a|

Used when:

• AggregateProcessor is updated (for window aggregate functions)
• AggregationIterator (for aggregate functions)