This text will elaborate on upgrading the PostgreSQL database from the 9.x version to the 12.x version. Upgrading the PostgreSQL server can be done by installing the newer version of Postgres alongside the current one and executing the pg_upgrade command with essential parameters. A manual backup and restore process is not required when we use the pg_upgrade as the command will automatically copy the data directory to the newer version. We will cover many requirements in-depth in this text to eradicate the numerous dynamic errors and challenges.
The PostgreSQL Config file and user database file must be backed up using pg_dump