Summary

Customer: Healthcare organization
Country: United States
Product Used: Ispirer Migration Service
Source Technology: Sybase ASA
Target Technology: Microsoft SQL Server
Project Scope: 300,000 LOC, 30 GB of data
Project Duration: 5 months

About Customer

Our customer is a multidisciplinary healthcare organization offering a full range of medical services. Operating in California, the client is a dynamic team of healthcare professionals who continually strive to be at the forefront of medical innovation and healthcare service delivery.

Challenge

The customer approached Ispirer willing to replace their outdated Sybase ASA with new Microsoft SQL Server database. The overall scope of the project consisted of more than 300,000 lines of code and 30 Gb of data.

Solution

Ispirer database migration services are a combination of automatic and manual migration which significantly reduces time for a project execution.

Usually, the specifics of each project imply close communication between the client and our team. Any code always has its own features that can complicate automatic conversion. We always arrange calls or correspond by mail to discuss controversial issues and determine the optimal solution to problems. This project is no exception.

During the migration of the database our team had several difficulties:

1) conversion of RAISERROR. The main issue was in getting a correct error message. RAISERROR works differently in Sybase ASA and MSSQL Server. While the source database showed the message correctly, Ispirer engineers had to add the message to the system table in the target database manually, call the RAISERROR and delete the message from the table. Since our team has automated this process in Ispirer Toolkit such a challenge won’t arise in future projects.

2) conversion of foreign keys with ON DELETE/ON UPDATE (CASCADE, SET NULL). Source database contained more than 1000 foreign keys. The solution for converting foreign keys is implemented in our tool with the help of creating additional triggers. But this approach was not the best in this project because it would degrade the target database performance. That is why our team converted foreign keys manually.

3) conversion of sequences. For this project our team developed a solution for effective automatic conversion of sequences, so such issues are now perfectly converted with the help of our software.

During the next testing stage our team dealt with more than 900 test cases provided by the client. This stage was complicated with a great number of procedures containing dynamic SQL that required manual efforts.