Blog: General approach to migrating Oracle applications with OCI interface to Microsoft SQL Server

When migrating a customer’s Oracle databases to Microsoft SQL Server I often face the problem of updating relevant applications. A broad range of our customers use the Oracle Call Interface (OCI) to develop their database applications. Oracle Call Interface is the comprehensive, native C language interface to Oracle Database. Our customers regularly use the OCI interface to create custom and packaged applications.

The problem

This interface is specific to Oracle and you can’t use it to connect to any other database platform. So, a solution was needed to discover the right path to effectively remediate the customer’s С or C++ applications to the Microsoft SQL Server.

Migrating Oracle apps with OCI interface to SQL Server problem

Application conversion and remediation proves to be a very important step for any database migration project. According to our 12-step methodology, this step requires approximately 25% of the effort of a project. As a result, you want to be as efficient as possible with this step. That’s why the discovery of a perfect solution is vital for the overall success of your database migration.

I discovered that the OCI interface is like the common ODBC interface. You can use ODBC interface to connect to various databases, including Oracle and SQL Server, that we use in the given project.

The solution

This approach allows for reuse of up to 98% of the source application code. More importantly, this approach allows you to keep the application logic with minimal changes. By using this approach, we can minimize the application remediation efforts.

Migrating Oracle apps with OCI interface to SQL Server solution

At DB Best, we use this general approach in various migration projects when migrating Oracle applications to other database platforms. Particularly, we utilized this approach when we migrated Oracle applications to Amazon RDS for PostgreSQL.