REVIEWER: Wendy Perry, lead database administrator for Central Vermont Public Service.

BACKGROUND: Organized in 1929 by the consolidation of eight electric companies, Central Vermont Public Service (CVPS) is the largest electric company in Vermont and serves close to 160,000 customers. J.D. Power & Associates ranked CVPS second in the East among midsized utilities for overall customer satisfaction.

PLATFORMS: CVPS has been using Sybase Replication Server for about 15 years, primarily to keep the query database updated with the online work management and facilities management transaction systems. CVPS combined the capabilities of Replication Server with Sybase Replication Agent for Oracle to allow the different tables stored in Sybase and Oracle to remain independent from each other but also allow the two databases to communicate and view tables from the other database.

PROBLEM SOLVED: A key requirement for CVPS to operate its business properly is to ensure that the Sybase and Oracle online transactional databases share information efficiently with each other as well as with the Sybase reporting database. With Sybase Replication Server and Replication Agent for Oracle, the databases were able to share information, enabling CVPS to perform complicated heterogeneous database communication at lower costs and without extensive rewrites.

PRODUCT FUNCTIONALITY: The CVPS solution combines the capabilities of Replication Server with Sybase Replication Agent for Oracle, which includes a restricted-use license of Sybase Enterprise Connect Data Access (ECDA). By integrating the Sybase and Oracle databases using the ECDA restricted license only for Oracle replication, CVPS reduced its overall licensing costs. A comprehensive middleware application would have been more costly and would not have performed as well when joining Sybase and Oracle tables. By using replication to transfer tables, CVPS was able to keep both systems separate so that each database does not have to see tables through the proxy. This approach has proven to be much more efficient and less costly than giving direct access to tables via middleware. CVPS already had Sybase Replication Server in house so that it just had to convert licenses and add the Replication Agent for Oracle option.

STRENGTHS: As many organizations use several databases from different vendors, they need to keep them separate but also integrated to keep the data they share in sync. Sybase Replication Server and Replication Agent for Oracle integrates Sybase and Oracle databases, allowing the heterogeneous databases to communicate with each without forcing a complete application rewrite. The tools also reduce database integration costs by allowing communication via replication rather than an expensive, comprehensive middleware solution.

WEAKNESSES: The biggest weakness that we have found with this solution is when an error occurs, it stops processing it its tracks. While the replication server is somewhat configurable for error handling, there are too many “it depends” scenarios for when an error occurs to be able to handle them with automation and avoid downtime. One other weakness is that replication does not tolerate large transactions very well. It can cause serious performance and other system problems if transactions are not managed appropriately. Apparently, this is addressed in the newest version. Because the replication agents read the transaction logs, it then has to apply the transactions to the replicate databases. So you need to be cognizant of this impact.

SELECTION CRITERIA: The CVPS IT team initially tested a middleware solution but soon realized this approach was a costly endeavor because they would have to rewrite a lot of code to make the data transfers between Oracle and Sybase databases perform properly. Realizing the Sybase Replication Server they had been using for about 15 years was a viable option for integrating the Sybase and Oracle databases, CVPS was able to keep the tables stored in Sybase and Oracle independent from each other, allowing them to communicate using Sybase Replication Agent for Oracle. This approach was a lot less expensive than a comprehensive middleware solution, and was a viable option because CVPS needs to replicate data in real time to keep the Work Management application running and to ensure customer service calls are handled efficiently.

DELIVERABLES: This solution provides real-time integration between our two systems.

VENDOR SUPPORT: We found that working with Sybase developers and the customer support team is much easier than working with most software vendors. With quick responses and builds they could test to fix the bugs, Sybase demonstrated fast turnaround times – especially in the test and development stages. Most vendors provide escalated support only for production systems, but Sybase offered prioritized support regardless of the development progress.

DOCUMENTATION: The product documentation was easy to understand, and installation and configuration can be done following the documentation. It made good use of examples.

Sybase Replication Server and Sybase Replication Agent for Oracle

Sybase, Inc.

One Sybase Drive

Dublin, CA 94568 USA

(925) 236-5000

http://www.sybase.com/

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