3. The method of claim 1 , further comprising: generating cardinality estimates for one or more query execution plans for the query using the statistics of one or more of the pre-defined queries that vertically overlap the query; and using the generated cardinality estimates to determine an optimal query execution plan for the query.
3. The method of claim 1 , further comprising: generating cardinality estimates for one or more query execution plans for the query using the statistics of one or more of the pre-defined queries that vertically overlap the query; and using the generated cardinality estimates to determine an optimal query execution plan for the query. 4. The method of claim 3 , wherein the statistics are used to improve a combined selectivity estimate of one or more predicates of the query.