Package org.apache.flink.table.api

Class Over

java.lang.Object

org.apache.flink.table.api.Over

@PublicEvolving
public final class Over
extends Object

Helper class for creating an over window. Similar to SQL, over window aggregates compute an aggregate for each input row over a range of its neighboring rows.

Java Example:

 Over.partitionBy("a").orderBy("rowtime").preceding("unbounded_range").as("w")
 

Scala Example:

 Over partitionBy 'a orderBy 'rowtime preceding UNBOUNDED_RANGE as 'w
 

Constructor Summary

Constructors

Constructor	Description
Over()

Method Summary

Modifier and Type	Method	Description
static OverWindowPartitionedOrdered	orderBy(org.apache.flink.table.expressions.Expression orderBy)	Specifies the time attribute on which rows are ordered.
static OverWindowPartitioned	partitionBy(org.apache.flink.table.expressions.Expression... partitionBy)	Partitions the elements on some partition keys.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Over

public Over()

Method Detail

partitionBy

public static OverWindowPartitioned partitionBy(org.apache.flink.table.expressions.Expression... partitionBy)

Partitions the elements on some partition keys.

Each partition is individually sorted and aggregate functions are applied to each partition separately.

Parameters:

partitionBy - list of field references

Returns:

an over window with defined partitioning

orderBy

public static OverWindowPartitionedOrdered orderBy(org.apache.flink.table.expressions.Expression orderBy)

Specifies the time attribute on which rows are ordered.

For streaming tables, reference a rowtime or proctime time attribute here to specify the time mode.

For batch tables, refer to a timestamp or long attribute.

Parameters:

orderBy - field reference

Returns:

an over window with defined order