A tool for setting up a distributed database system

Replication is becoming increasingly popular as a way of distributing data; however, most companies aren't prepared to support the additional complexity that comes with a distributed database. I know from my distributed database experience that good tools can make a big difference, not only in assisting the start of the replication, but in the administrative tasks afterward. Replic-Action from Casahl Technologies is a replication software that assists with distributing data between the most popular data sources. Replic-Action is one of the best replication tools available because of its rich feature set and easy-to-use screens and because of what it does after you set up replication.


Replic-Action provides replication-tracking and status- checking screens. Your operations and administrative staff members will find that Replic-Action's job administration, restart, error notification, and logging capabilities make this product easy to use when you're supporting distributed databases.

Table 1 shows a partial list of data sources that you can access through Replic-Action. For a full list, see Casahl's product catalogs and Web site. The ODBC drivers for the data sources listed ship with Replic-Action. Casahl plans to support OLE DB in future releases.

Replic-Action lets you access data sources rather than just databases. You can move data among data sources such as text files, spreadsheets, email, and data warehouses. Also, you can replicate email, newsgroup discussion threads, and live Excel spreadsheets.

Screen 1, page 60, shows the Composer Objects, which include the Replic-Action Jobs and Replic-Action Component Objects. These Composer Objects are the administrator program tools that you use to set up, configure, and program a replication job.

Replic-Action has built-in support for enterprise resource planning (ERP) systems, such as those offered by PeopleSoft, SAP, and Baan. Replic-Action recognizes certain objects and formats such as SAP R/3's Business Application Programming Interface (BAPI), Remote Function Call (RFC) Tables and Application Link Enabling/Internal Documentation (ALE/IDOC). Screen 2, page 60, shows SAP's replication properties and functions that Replic-Action can work with. This capability, for example, lets someone using an SAP system receive a purchase order that someone else created with a PeopleSoft application.

Replic-Action provides merge replication with conflict resolution, snapshot and transactional replication, data scrubbing, transformations, column mapping, Visual Basic (VB) and Java scripting, workflow triggering, and old-fashioned import/export capabilities.
Add to that list enterprise-level functionality such as scalability, three-tiered architecture, Micro-soft Transaction Server (MTS) and COM support, load balancing, and realtime transaction processing.

Application Examples

The following application scenarios describe ways in which you can use Replic-Action with any DBMS.

Purchase order workflow. You can use Replic-Action as the middle tier between Microsoft Exchange, Outlook, and SQL Server. After you enter purchase order data into a SQL Server database, you can use Exchange and Outlook for the approval routing process. Also, you can write the application to support mobile users who are disconnected from the network. This feature lets you easily upload orders (e.g., entered on a remote laptop) to a mainframe database after you connect to the network again. As is typical in a mobile application, Replic-Action makes it easy to download data to a laptop.

Mainframe integration. Replic-Action can move data between SQL Server and a DB2 or other mainframe database, on a realtime or periodic basis (e.g., hourly, nightly, and weekly). Replic-Action uses Real-Time Transaction Processing (RTTP) for realtime data and replication for periodically moving data.

Microsoft Access to an enterprise-class database. Two-tier applications that attach database tables to Microsoft Access are popular because they're easy to create. However, most companies discover that using attached tables limits scalability. Using Replic-Action instead of attached tables gives you more control and better scalability because you write less code and use better error checking and logging. Also, you take advantage of Microsoft Access' smaller number of connections before overloading the DBMS.

Reporting and data mining in SAP R/3. With the proper security, users in a realtime-enabled Excel spreadsheet can access SAP R/3 through Replic-Action. This combination lets multiple users work with the same spreadsheet simultaneously.

PeopleSoft to SAP R/3. Users who want to transfer data between PeopleSoft and SAP databases can choose a solution. Replic-Action lets you transfer data in realtime through RTTP or periodically with replication.

Lotus Notes to Microsoft Exchange. Replication is easy with Replic-Action's built-in connectors to each system. Replic-Action has worked with Lotus Notes for many years and is considered a solid player in this arena.

Testing Replic-Action

I installed Replic-Action on my 90MHz Pentium I laptop with 32MB of memory and Windows 95. I then completed bidirectional replication between a Microsoft Access Northwind database and a SQL Server 7.0 Northwind database that was on the same machine. The replication worked with the ODBC connection to SQL Server 7.0.

Then I tested a 4-way 400MHz Pentium III server with 4GB of memory, 40GB of disk space, and Windows NT 4.0, Service Pack 4 (SP4). To test bidirectional replication between a SQL Server 6.5 (SP5a) database and a Microsoft Exchange 5.5 folder, I chose the Authors table from the Pubs database and selected a new empty public folder called Authors. I started the replication, and before I could Alt-Tab to the Exchange window, Replic-Action had put the SQL Server records in the Exchange folder. Then I changed a record in the Exchange folder to see whether Repli-Action would change the record in the folder. Before I could display the records from the SQL Server table, Replic-Action had made the change in the folder.

The installation on both systems was easy and straightforward. Replic-Action recognizes the environment that you're installing to and determines the right mix of programs, services, and DLLs. Preparation before installation was minimal and consisted mostly of verifying domain and server names.

The Learning Curve

Replic-Action from Casahl Technologies simplifies replication. If you need to perform simple replication tasks, you can accomplish a lot in a short time. However, as with any product that has many features and flexibility, prepare to spend time learning how to do more complex jobs, such as replication requiring a data transformation. If you're a novice to the database world or replication, you'll spend more time learning the business and application complexities of distributed data than you'll spend learning this tool.

The documentation contains several tutorials, demos, and white papers. For a novice or expert, the Getting Started manual is the best place to start.

When you need to distribute many data objects with different databases and different application systems that share data, Replic-Action is worth the money. Replic-Action also provides great support of administrative tasks after replication.