Copyright © 2016 MariaDB. All rights reserved.
Get the Free Gartner Report on Optimizing with Open Source
Note that Parallel Replication is about how a replication slave applies updates received from the master. SELECT statements do not modify the database and thus are never replicated. So Parallel Replication has no relevance to SELECT statements.
I do not know if tokudb has optimisations for running a single SELECT in parallel. The server layer of mariadb does not.
Download MariaDB and start working immediately! You can also get subscription details and learn more about the advantages of MariaDB's additional service offers.