Recently I got a work to transfer data from database A to database B for 5 tables.
After quick research, decided to write in Java. Used simple JDBC calls and completed the work in 42 hours.
During this transfer there are few conditions, we need to check to update other tables too.
1. No cost on ETL tools.
2. Easy to mange through Crontab in Linux.
3. As a Java developer I have complete control on my Code.
For bigger jobs, definitely we need ETL tools.