com.espertech.esper.epl.join.exec.base
Interface JoinExecTableLookupStrategy

All Known Implementing Classes:

CompositeTableLookupStrategy, FullTableScanLookupStrategy, FullTableScanUniqueValueLookupStrategy, HistoricalTableLookupStrategy, IndexedTableLookupStrategy, IndexedTableLookupStrategyExpr, IndexedTableLookupStrategySingle, IndexedTableLookupStrategySingleExpr, InKeywordMultiTableLookupStrategyExpr, InKeywordSingleTableLookupStrategyExpr, JoinExecTableLookupStrategyVirtualDW, SortedTableLookupStrategy

public interface JoinExecTableLookupStrategy

Strategy for looking up, in some sort of table or index, an event, potentially based on the events properties, and returning a set of matched events.

Method Summary

LookupStrategyDesc	getStrategyDesc()
java.util.Set<EventBean>	lookup(EventBean theEvent, Cursor cursor, ExprEvaluatorContext exprEvaluatorContext) Returns matched events for a event to look up for.

Method Detail

lookup

java.util.Set<EventBean> lookup(EventBean theEvent,
                                Cursor cursor,
                                ExprEvaluatorContext exprEvaluatorContext)

Returns matched events for a event to look up for. Never returns an empty result set, always returns null to indicate no results.

Parameters:

theEvent - to look up

cursor - the path in the query that the lookup took

exprEvaluatorContext - expression evaluation context

Returns:

set of matching events, or null if none matching

getStrategyDesc

LookupStrategyDesc getStrategyDesc()