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Best Practices for Using PowerExchange CDC for Oracle

This post was written by guest author Justin Passofaro, Principal Data Management Consultant at SSG, a consulting practice focused on innovative ways to leverage data for better business decisions.

Using PowerExchange CDC for OracleConfiguring your Oracle environment for using PowerExchange CDC can be challenging, but there are some best practices you can follow that will greatly simplify the process. There are two major factors to consider when approaching this: latency requirements for your data and the ability to restart your environment.

Data Latency Requirements

The first factor that will effect latency of your data is the location of your PowerExchange CDC installation. From a best practice perspective, it is optimal to install the PowerExchange Listener on the source database server as this eliminates the need to pass data across the network and will provide the smallest amount of latency from source to target.

The volume of data that PowerExchange CDC has to process can also have a significant impact on performance. There are several items in addition to the changed data that can effect performance, including, but are not limited to, Oracle catalog dumps, Oracle workload monitor customizations and other non-Oracle tools that use the redo logs. You should conduct a review of all the processes that access Oracle redo logs, and make an effort to minimize them in terms both volume and frequency. For example, you could monitor the redo log switches and the creation of archived log files to see how busy the source database is. The size of your production archive logs and knowing how often they are being created will provide the information necessary to properly configure PowerExchange CDC.

Environment Restart Ability

When certain changes are made to the source database environment, the PowerExchange CDC process will need to be stopped and restarted. The amount of time this restart takes should be considered whenever this needs to occur. PowerExchange CDC must be restarted when any of the following changes occur:

–          A change is made to the schema or a table that is part of the CDC process

–          An existing Capture Registration is changed

–          A change is made to the PowerExchange configuration files

–          An Oracle patch is applied

–          An Operating System patch or upgrade is applied

–          A PowerExchange version upgrade or service pack is applied

If using the CDC with LogMiner, a copy of the Oracle catalog must be placed on the archive log in order to function properly. The frequency of these copies is site-specific and will have an impact on the amount of time it will take to restart the CDC process.

Once your PowerExchange CDC process is in production, any changes to the environment must have extensive impact analysis performed to ensure the integrity of the data and the transactions remains intact upon restart. Understanding the configurable parameters in the PowerExchange configuration files that will assist restart performance is of the utmost importance.

Even with the challenges presented when configuring PowerExchange CDC for Oracle, there are trusted and proven methods that can significantly improve your ability to complete this process and have real time or near real time access to your data. At SSG, we’re committed to always utilizing best practice methodology with our PowerExchange Baseline Deployments.  In addition, we provide in-depth knowledge transfer to set end users up with a solid foundation for optimizing PowerExchange functionality.

Visit the Informatica Marketplace to learn more about SSG’s Baseline Deployment offerings.