UserDefinedAggregateFunction (Spark 3.5.2 JavaDoc)

Object
- org.apache.spark.sql.expressions.UserDefinedAggregateFunction

All Implemented Interfaces:

java.io.Serializable

Deprecated.
UserDefinedAggregateFunction is deprecated. Aggregator[IN, BUF, OUT] should now be registered as a UDF via the functions.udaf(agg) method.
```
public abstract class UserDefinedAggregateFunction
extends Object
implements scala.Serializable
```
The base class for implementing user-defined aggregate functions (UDAF).

Since:

1.5.0

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor and Description

UserDefinedAggregateFunction()
Deprecated.

Constructors
Constructor and Description
`UserDefinedAggregateFunction()` Deprecated.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`Column`	`apply(Column... exprs)` Deprecated. Creates a `Column` for this UDAF using given `Column`s as input arguments.
`Column`	`apply(scala.collection.Seq<Column> exprs)` Deprecated. Creates a `Column` for this UDAF using given `Column`s as input arguments.
`abstract StructType`	`bufferSchema()` Deprecated. A `StructType` represents data types of values in the aggregation buffer.
`abstract DataType`	`dataType()` Deprecated. The `DataType` of the returned value of this `UserDefinedAggregateFunction`.
`abstract boolean`	`deterministic()` Deprecated. Returns true iff this function is deterministic, i.e.
`Column`	`distinct(Column... exprs)` Deprecated. Creates a `Column` for this UDAF using the distinct values of the given `Column`s as input arguments.
`Column`	`distinct(scala.collection.Seq<Column> exprs)` Deprecated. Creates a `Column` for this UDAF using the distinct values of the given `Column`s as input arguments.
`abstract Object`	`evaluate(Row buffer)` Deprecated. Calculates the final result of this `UserDefinedAggregateFunction` based on the given aggregation buffer.
`abstract void`	`initialize(MutableAggregationBuffer buffer)` Deprecated. Initializes the given aggregation buffer, i.e.
`abstract StructType`	`inputSchema()` Deprecated. A `StructType` represents data types of input arguments of this aggregate function.
`abstract void`	`merge(MutableAggregationBuffer buffer1, Row buffer2)` Deprecated. Merges two aggregation buffers and stores the updated buffer values back to `buffer1`.
`abstract void`	`update(MutableAggregationBuffer buffer, Row input)` Deprecated. Updates the given aggregation buffer `buffer` with new input data from `input`.

Methods inherited from class Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - UserDefinedAggregateFunction
```
public UserDefinedAggregateFunction()
```
    Deprecated.
- Method Detail
  - apply
```
public Column apply(Column... exprs)
```
    Deprecated.
    
    Creates a Column for this UDAF using given Columns as input arguments.
    
    Parameters:
    
    exprs - (undocumented)
    
    Returns:
    
    (undocumented)
    
    Since:
    
    1.5.0
  - apply
```
public Column apply(scala.collection.Seq<Column> exprs)
```
    Deprecated.
    
    Creates a Column for this UDAF using given Columns as input arguments.
    
    Parameters:
    
    exprs - (undocumented)
    
    Returns:
    
    (undocumented)
    
    Since:
    
    1.5.0
  - bufferSchema
```
public abstract StructType bufferSchema()
```
    Deprecated.
    
    A StructType represents data types of values in the aggregation buffer. For example, if a UserDefinedAggregateFunction's buffer has two values (i.e. two intermediate values) with type of DoubleType and LongType, the returned StructType will look like
    new StructType() .add("doubleInput", DoubleType) .add("longInput", LongType)
    The name of a field of this StructType is only used to identify the corresponding buffer value. Users can choose names to identify the input arguments.
    
    Returns:
    
    (undocumented)
    
    Since:
    
    1.5.0
  - dataType
```
public abstract DataType dataType()
```
    Deprecated.
    
    The DataType of the returned value of this UserDefinedAggregateFunction.
    
    Returns:
    
    (undocumented)
    
    Since:
    
    1.5.0
  - deterministic
```
public abstract boolean deterministic()
```
    Deprecated.
    
    Returns true iff this function is deterministic, i.e. given the same input, always return the same output.
    
    Returns:
    
    (undocumented)
    
    Since:
    
    1.5.0
  - distinct
```
public Column distinct(Column... exprs)
```
    Deprecated.
    
    Creates a Column for this UDAF using the distinct values of the given Columns as input arguments.
    
    Parameters:
    
    exprs - (undocumented)
    
    Returns:
    
    (undocumented)
    
    Since:
    
    1.5.0
  - distinct
```
public Column distinct(scala.collection.Seq<Column> exprs)
```
    Deprecated.
    
    Creates a Column for this UDAF using the distinct values of the given Columns as input arguments.
    
    Parameters:
    
    exprs - (undocumented)
    
    Returns:
    
    (undocumented)
    
    Since:
    
    1.5.0
  - evaluate
```
public abstract Object evaluate(Row buffer)
```
    Deprecated.
    
    Calculates the final result of this UserDefinedAggregateFunction based on the given aggregation buffer.
    
    Parameters:
    
    buffer - (undocumented)
    
    Returns:
    
    (undocumented)
    
    Since:
    
    1.5.0
  - initialize
```
public abstract void initialize(MutableAggregationBuffer buffer)
```
    Deprecated.
    
    Initializes the given aggregation buffer, i.e. the zero value of the aggregation buffer.
    The contract should be that applying the merge function on two initial buffers should just return the initial buffer itself, i.e. merge(initialBuffer, initialBuffer) should equal initialBuffer.
    
    Parameters:
    
    buffer - (undocumented)
    
    Since:
    
    1.5.0
  - inputSchema
```
public abstract StructType inputSchema()
```
    Deprecated.
    
    A StructType represents data types of input arguments of this aggregate function. For example, if a UserDefinedAggregateFunction expects two input arguments with type of DoubleType and LongType, the returned StructType will look like
    new StructType() .add("doubleInput", DoubleType) .add("longInput", LongType)
    The name of a field of this StructType is only used to identify the corresponding input argument. Users can choose names to identify the input arguments.
    
    Returns:
    
    (undocumented)
    
    Since:
    
    1.5.0
  - merge
```
public abstract void merge(MutableAggregationBuffer buffer1,
                           Row buffer2)
```
    Deprecated.
    
    Merges two aggregation buffers and stores the updated buffer values back to buffer1.
    This is called when we merge two partially aggregated data together.
    
    Parameters:
    
    buffer1 - (undocumented)
    
    buffer2 - (undocumented)
    
    Since:
    
    1.5.0
  - update
```
public abstract void update(MutableAggregationBuffer buffer,
                            Row input)
```
    Deprecated.
    
    Updates the given aggregation buffer buffer with new input data from input.
    This is called once per input row.
    
    Parameters:
    
    buffer - (undocumented)
    
    input - (undocumented)
    
    Since:
    
    1.5.0

Class UserDefinedAggregateFunction

Constructor Summary

Method Summary

Methods inherited from class Object

Constructor Detail

UserDefinedAggregateFunction

Method Detail

apply

apply

bufferSchema

dataType

deterministic

distinct

distinct

evaluate

initialize

inputSchema

merge

update