Package org.apache.calcite.rel.core

Class Window.Group

java.lang.Object

org.apache.calcite.rel.core.Window.Group

Enclosing class:

Window

public static class Window.Group
extends Object

Group of windowed aggregate calls that have the same window specification.

The specification is defined by an upper and lower bound, exclusion clause, and also has zero or more partitioning columns.

A window is either logical or physical. A physical window is measured in terms of row count. A logical window is measured in terms of rows within a certain distance from the current sort key.

For example:

• ROWS BETWEEN 10 PRECEDING and 5 FOLLOWING is a physical window with an upper and lower bound;
• RANGE BETWEEN INTERVAL '1' HOUR PRECEDING AND UNBOUNDED FOLLOWING is a logical window with only a lower bound;
• RANGE INTERVAL '10' MINUTES PRECEDING (which is equivalent to RANGE BETWEEN INTERVAL '10' MINUTES PRECEDING AND CURRENT ROW) is a logical window with an upper and lower bound.

Field Summary

Fields

Modifier and Type	Field	Description
final com.google.common.collect.ImmutableList<Window.RexWinAggCall>	aggCalls	List of Window.RexWinAggCall objects, each of which is a call to a SqlAggFunction.
final RexWindowExclusion	exclude
final boolean	isRows
final ImmutableBitSet	keys
final RexWindowBound	lowerBound
final RelCollation	orderKeys
final RexWindowBound	upperBound

Constructor Summary

Constructors

Constructor	Description
Group(ImmutableBitSet keys, boolean isRows, RexWindowBound lowerBound, RexWindowBound upperBound, RexWindowExclusion exclude, RelCollation orderKeys, List<Window.RexWinAggCall> aggCalls)

Method Summary

Modifier and Type	Method	Description
RelCollation	collation()
boolean	equals(@Nullable Object obj)
List<AggregateCall>	getAggregateCalls(Window windowRel)	Presents a view of the Window.RexWinAggCall list as a list of AggregateCall.
int	hashCode()
boolean	isAlwaysNonEmpty()	Returns if the window is guaranteed to have rows.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

keys

public final ImmutableBitSet keys

isRows

public final boolean isRows

lowerBound

public final RexWindowBound lowerBound

upperBound

public final RexWindowBound upperBound

exclude

public final RexWindowExclusion exclude

orderKeys

public final RelCollation orderKeys

aggCalls

public final com.google.common.collect.ImmutableList<Window.RexWinAggCall> aggCalls

List of Window.RexWinAggCall objects, each of which is a call to a SqlAggFunction.

Constructor Details

Group

public Group(ImmutableBitSet keys,
 boolean isRows,
 RexWindowBound lowerBound,
 RexWindowBound upperBound,
 RexWindowExclusion exclude,
 RelCollation orderKeys,
 List<Window.RexWinAggCall> aggCalls)

Method Details

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(@Nullable Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

collation

public RelCollation collation()

isAlwaysNonEmpty

public boolean isAlwaysNonEmpty()

Returns if the window is guaranteed to have rows. This is useful to refine data type of window aggregates. For instance sum(non-nullable) over (empty window) is NULL.

Returns:

true when the window is non-empty

See Also:

• SqlWindow.isAlwaysNonEmpty()
• SqlOperatorBinding.hasEmptyGroup()
• SqlValidatorImpl.resolveWindow(org.apache.calcite.sql.SqlNode, org.apache.calcite.sql.validate.SqlValidatorScope)

getAggregateCalls

public List<AggregateCall> getAggregateCalls(Window windowRel)

Presents a view of the Window.RexWinAggCall list as a list of AggregateCall.