22. The method of claim 1 , further comprising, in creating the execution plan, analyzing of a query includes determining if the query includes a subquery.
22. The method of claim 1 , further comprising, in creating the execution plan, analyzing of a query includes determining if the query includes a subquery. 23. The method of claim 22 , wherein if a query includes a subquery, creating the execution plan includes replacing the subquery in the query with a new data stream and creating a new query based on the subquery that generates messages into the new data stream.