# Which Problems Are Solved
After migrating the access token events in #7822, milestones based on
authentication, resp. theses events would not be reached.
# How the Problems Are Solved
Additionally use the `oidc_session.Added` event to check for
`milestone.AuthenticationSucceededOnInstance` and
`milestone.AuthenticationSucceededOnApplication`.
# Additional Changes
None.
# Additional Context
- relates to #7822
- noticed internally
This implementation increases parallel write capabilities of the eventstore.
Please have a look at the technical advisories: [05](https://zitadel.com/docs/support/advisory/a10005) and [06](https://zitadel.com/docs/support/advisory/a10006).
The implementation of eventstore.push is rewritten and stored events are migrated to a new table `eventstore.events2`.
If you are using cockroach: make sure that the database user of ZITADEL has `VIEWACTIVITY` grant. This is used to query events.