ignite is not optimized for count queries. it visits each object to do the count and doesn't do the count off of an index (or some cached store). seems kind of silly, especially if you have a count on indexed fields.
i think query cancellation only works within the API. I think you can either set a timeout for the query or you can cancel it with the handle to the cursor. i doubt cancelling through JDBC works. -- Sent from: http://apache-ignite-users.70518.x6.nabble.com/
