Package org.apache.calcite.adapter.enumerable

Interface WinAggImplementor

All Superinterfaces:

AggImplementor

All Known Implementing Classes:

RexImpTable.LagImplementor, RexImpTable.LeadImplementor, StrictWinAggImplementor

public interface WinAggImplementor
extends AggImplementor

Implements a windowed aggregate function by generating expressions to initialize, add to, and get a result from, an accumulator. Windowed aggregate is more powerful than regular aggregate since it can access rows in the current partition by row indices. Regular aggregate can be used to implement windowed aggregate.

This interface does not define new methods: window-specific sub-interfaces are passed when implementing window aggregate.

See Also:

• StrictWinAggImplementor
• RexImpTable.FirstLastValueImplementor
• RexImpTable.RankImplementor
• RexImpTable.RowNumberImplementor

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static enum	WinAggImplementor.SeekType	Allows to access rows in window partition relative to first/last and current row.

Method Summary

Modifier and Type	Method	Description
boolean	needCacheWhenFrameIntact()

Methods inherited from interface org.apache.calcite.adapter.enumerable.AggImplementor

getStateType, implementAdd, implementReset, implementResult

Method Details

needCacheWhenFrameIntact

boolean needCacheWhenFrameIntact()