We are trying to devise a backup strategy for Azure Flexible Server. Can we use the native pgdumpall as a backup and restore mechanism, I am able to take a dumpall by excluding azure default database (as we are not super user in managed server)
pg_dumpall - Azure Database for PostgreSQL - permission denied for database "azure_maintenance"
Can we restore the dump that we create somehow in the managed postgres flexible server, I am unable to find any support in this regard.
You should be able to restore the dump to Flexible server. See if any of these docs help however for the link you shared Yes, we do not allow dump all as some of the internal DBs are not exposed to customers due to security.
Upgrade using dump and restore - Azure Database for PostgreSQL | Microsoft Docs Dump and restore - Azure Database for PostgreSQL - Single Server | Microsoft Docs