Question : What does IPv6 have in store for us, will we have any trouble talking to remote sites?

We have plent of IPv4 addresses for our HQ and COLO. However, we have sites all over america and latin america. They connected via DMVPN.

Will we have problems in the future if say one or more sites in the US or Latin America can only give an IPv6 address?

Answer : What does IPv6 have in store for us, will we have any trouble talking to remote sites?

You need to change at DB_B AS well if u r planning to modify the procedure proc_b in future to avoid time stamp mismatch

please see the refernce from the link

http://psoug.org/reference/db_link.html

Server-side PL/SQL users (ie in DB_A ) can choose to use the signature dependency mode if they have a distributed system and they want to avoid possible unnecessary recompilations.

Client-side PL/SQL users (ie in DB_B) should set the parameter to SIGNATURE. This allows:
1. Installation of new applications at client sites, without the need to recompile procedures.

2.  Ability to upgrade the server, without encountering timestamp mismatches.