However, the two processes are separate on the router, and the two routing tables are separate as well.
IPv4 routing is enabled by default.
IPv6 routing is disabled by default, and must be enabled with:
ipv6 unicast-routing
If IPv6 routing is disabled, the router will be able to send and receive IPv6 traffic, but will not route IPv6 traffic (=will not forward it between networks).
A connected network route is automatically added for each connected network.
A local host route is automatically added for each address configured on the router.
If the main route to the destination was learned via OSPF, for example, you'll need to set the static route's AD to higher than 110, because OSPF's AD is 110.