We want to know if there are any open/known issues that we may face post-migration of the DB cluster from centos7/RHEL7/OEL7 to RHEL8.
Depends on the method you choose to perform this migration ?
--> The method will depend on data size and the complexity of the data upon which the method will be decided.
Ex -
1. For less critical/small DB size, This Can be possible with the dump and restore with the small outage.
2. For a Highly transactional system most probably streaming replication will be the method.
3. For Less transactional and less complex data (No extensions like Timescale/PostGIS etc.. .) most probably logical replication will be the method.
Hence, I opened this discussion to understand if there are any other known issues that the PostgreSQL community should be aware of while migrating the database from centos7/RHEL7/OEL7 to RHEL8 via different methods.
If you are using pg_dump and pg_restore for the initial data copy,
followed by logical replication, then, it should be technically okay.
We came across one issue regarding collation(https://wiki.postgresql.org/wiki/Locale_data_changes), the solution for which is to reindex or use logical replication. In a similar way, we want to understand if there are any other known issues that the community should be aware of.