com.espertech.esper.epl.join.base
Interface HistoricalIndexLookupStrategy

All Known Implementing Classes:

HistoricalIndexLookupStrategyComposite, HistoricalIndexLookupStrategyIndex, HistoricalIndexLookupStrategyIndexSingle, HistoricalIndexLookupStrategyInKeywordMulti, HistoricalIndexLookupStrategyInKeywordSingle, HistoricalIndexLookupStrategyNoIndex, HistoricalIndexLookupStrategySorted

public interface HistoricalIndexLookupStrategy

Strategy for use in poll-based joins to reduce a cached result set (represented by EventTable), in which the cache result set may have been indexed, to fewer rows following the join-criteria in a where clause.

Method Summary

java.util.Iterator<EventBean>	lookup(EventBean lookupEvent, EventTable[] index, ExprEvaluatorContext context) Look up into the index, potentially using some of the properties in the lookup event, returning a partial or full result in respect to the index.
java.lang.String	toQueryPlan()

Method Detail

lookup

java.util.Iterator<EventBean> lookup(EventBean lookupEvent,
                                     EventTable[] index,
                                     ExprEvaluatorContext context)

Look up into the index, potentially using some of the properties in the lookup event, returning a partial or full result in respect to the index.

Parameters:

lookupEvent - provides properties to use as key values for indexes

index - is the table providing the cache result set, potentially indexed by index fields

Returns:

full set or partial index iterator

toQueryPlan

java.lang.String toQueryPlan()