There is no feature in PostgreSQL that allows for locking out a user after a few failed attempts. Hence, there is no account lockout policy for Postgres repository in TDV

If you look at the this below link it talks about the authentication methods supported by PostgreSQL (https://www.postgresql.org/docs/current/static/auth-methods.html). 

There doesn't seem to be anything out of the box. It is possible to implement it using PAM authentication which is essentially a pluggable model. It is also quite possible that LDAP or RADIUS methods could have the lock out implemented within those systems.

Having said all this, PostgreSQL instance (repository instance) for TDV is locked out for any access from outside the machine. It only allows localhost access. The user who has repository access is configured during installation time so that is the only user account that will be used. It is not supposed to be used for access by any other user because this instance should be dedicated for TDV's repository use only.