Function Connection.purgeResult

When the server responds to a command that produces a result set, it queues the whole set of corresponding packets over the current connection. Before that Connection can embark on any new command, it must receive all of those packets and junk them.

As of v1.1.4, this is done automatically as needed. But you can still call this manually to force a purge to occur when you want.

See Also

http://www.mysqlperformanceblog.com/2007/07/08/mysql-net_write_timeout-vs-wait_timeout-and-protocol-notes/