Controls whether a plan is returned when a cursor is opened.
In early versions of the software, each time an OPEN was done on a cursor, the server would return in the SQLCA sqlerrmc field a string representing the query plan (limited to 70 bytes). A more complete description can be obtained using the EXPLAIN statement or the PLAN function. For this reason, computing and returning the query plan on an OPEN is needed only for compatibility with old applications. The query_plan_on_open option controls whether the plan is returned on an OPEN.