We are planning to migrate our application written in java to Azure. The Application database is in oracle and we want to re write it in Azure SQL. What should be the best strategy to keep both on prem and cloud databases in sync.
One approach could be to call current on-prem java API's from newly deployed Azure app. But this would be a distributed transaction.
If you need real-time replication, then you will need tools like Golden Gate or Qlik Replicate. For example, you can establish a VPN and use a tool like Oracle Golden Gate to keep your Oracle database and Azure SQL Database in sync. Here you will find how to create the connection.
If you don't need real-time replication, you can also consider using Azure Data Factory which has a connector for Oracle.