We add FORCE INDEX to revision because probably we have hit a MariaDB
bug that can potentially create an outage on pages with thousands of
revisions due to extreme resource usage by this query when using the
wrong index page_user_timestamp, instead of page_timestamp.
This is considered to be a hack, and once we are in the clear, I promise
to review this an try to get a saner execution path (both in MySQL and
in PHP.
Bug: T116557
Change-Id: I41853da5c0e1a15efad5594eff0cee62be1ad9a4
Follows-up e4ac1ef. A lot of this class gets its own cache object
in key-generation methods because of legacy compat with public
methods and because of how wfMemcKey used to be.
However where possible, we should encourage passing $cache
so that makeKey() can be used on the same instance that uses
the key.
This is a no-op since it's exactly the same object.
Change-Id: Ib3c31110176659a9175679eb716369e7f0a1d3b2
