Displaying subquery cache information

The set statistics subquerycache on command displays the number of cache hits and misses and the number of rows in the cache for each subquery. The following example shows subquery cache statistics:

set statistics subquerycache on

select type, title_id
from titles
where price > all
    (select price
        from titles
        where advance < 15000)
Statement: 1  Subquery: 1  cache size: 75  hits: 4925  misses: 75

If the statement includes subqueries on either side of a union, the subqueries are numbered sequentially through both sides of the union.