Run subquery N (at nesting level N).
This message shows the place where the subquery execution takes place in the execution of the outer query. Adaptive Server executes the subquery at the point in the outer query where it need to be run least often.
The plan for this subquery appears later in the output for the subquery’s nesting level. The first variable in this message is the subquery number; the second variable is the subquery nesting level.