Precede an SQL statement by DIAGNOSE to produce a detailed explanation of how the optimizer will handle the query.


DIAGNOSE query-statement


The query is not executed by Kognitio, when preceded by DIAGNOSE, rather the details of the optimizer’s execution plan are returned.

The DIAGNOSE statement is generally used only for in-depth software diagnosis, because using the output requires considerable knowledge of the underlying software architecture. However, when placing a call to the Kognitio SQL Guide, March 2016
Kognitio Helpdesk, you may be asked to issue this statement and report the results to help identify a problem.