Can SQL Server Change Data capture (CDC) log rows to an external DB?

Question

I have not used SQL Server CDC before, but to my understanding it works like this:

1. business data changes in source DB, e.g. SQL Server
2. CDC has been configured to track certain table/column changes, which it reads asynchronously from business data server transactional logs

I have two question: 1. Can CDC be triggered to store e.g. some DB rows to an external DB, or do any eventual database rows that are being created from the transaction logs, need to be stored back to the source DB? 2. Can CDC read from the business DB transactional logs and create new rows to a NoSQL DB?

Thanks!

Answer 1

CDC is just the component that exposes the changes. It is strictly tied to the host database where the changes occur. CDC is useless without an application you provide which consumes the changes. This application of yours can do anything with the changes, including storing them anywhere you fancy. You just have to implement this application.

• user1340582: Ok so the information can be collected from CDC. If I would like to create a new audit row to another DB containing the changed information, what would that application look like? I mean, is CDC able to trigger e.g. a script file that would do the transfer? Also, how is CDC configured and can it be configured through some e.g. web page?
• Remus Rusanu: Please start by reading the specifications at About Change Data Capture, Work with Change Data and more You can't skip to implementation w/o understanding what CDC is
• Hein: Good answer Remus. There are products which can help you solve this problem. I work for Attunity which sells such product 'Replicate'. It is made to 'consume' changes (SQLserver - Tlog, Oracle redo/arch, and many more), and apply or store them to 'other', or the same targets: SQLserver, Oracle, Netezza, Vertica, "the cloud", Hadoop, Postgress, and many more are supported. Define your source DB, select tables, define target, 'click' to Replicate. Optional transformations and filters. Hope this helps!