Performance tuning of the Intercall database of Deutsche Telekom. The Intercall database processes data from roaming calls made by Deutsche Telekom customers around the world. The roaming times are processed, which are ultimately decisive for the roaming amount on the invoice of each customer. The task was a complete performance tuning of this database. The database was developed using Oracle and PL SQL.

• Stabilization of the existing application and increasing the performance of the existing application.
• Efficient SQL statements (written in PL-SQL.
• Reduce hard disk access.
• Optimize existing PL-SQL code.
• Testing and documentation (user and technical).