Hi Ryan,
Good question!
Just to be clear, the generic partitioning handler is still supported in all MySQL 5.7 releases, although it is deprecated in 5.7.17 and later. (Note that "deprecated" is not the same as "removed".) Partitioned tables created in older versions of MySQL continue to work in 5.7. The generic partitioning handler is removed in MySQL 8.0, so that such tables no longer work in 8.0.
To upgrade partitioned InnoDB tables created in older versions of MySQL, you can do either of the following:
1. Upgrade all such tables at the same time using mysql_upgrade (see
https://dev.mysql.com/doc/refman/5.7/en/mysql-upgrade.html).
2. Upgrade such tables one at a time in the mysql client using
ALTER TABLE table_name UPGRADE PARTITIONING (see
https://dev.mysql.com/doc/refman/5.7/en/alter-table.html).
Both of the methods just described work in MySQL 5.7.9 and later.
This information is all available in the MySQL 5.7 Manual, but it's sort of scattered in various places. I'm adding an item covering this issue to
https://dev.mysql.com/doc/refman/5.7/en/upgrading-from-previous-series.html; this should be available in the online Manual later today. Thanks for pointing this out to us!
cheers
Jon Stephens
MySQL Documentation Team @ Oracle
MySQL Dev Zone
MySQL Server Documentation
Oracle