As your data volumes grow, your operations slow down. 

Data-ingestion - extraction of all underlying data, transformation, and loading in a storage destination (such as a PostgreSQL or MySQL database) - becomes sluggish, impacting processes down the line. Affecting your data analytics and time to insights. 

Change Data Capture (CDC) makes data available faster, more efficiently, and without sacrificing data accuracy. 

What is Change Data Capture (CDC)?

Change Data Capture (CDC) is a process of identifying the changes in a database, data warehouse, or data lake and replicating those changes to another destination storage.

You could replicate the entire source database. In this design pattern called “bulk load updating”, you take a database dump and move all data to a new location - the replica database. 

However, this method is not as efficient, since you replicate data that has already been replicated in the past. Bulk replication also doesn’t scale - as your data volumes increase your network latency and processing bottlenecks slow down database replication.

Detecting which table rows have been changed (added, deleted, altered), and replicating those changes makes the entire replication process orders of magnitude more efficient. 

In modern data environments, where the volume of data keeps growing, CDC is the only viable data replication technique that scales with your data operations.

Why do you need CDC?

CDC has multiple advantages:

1. Faster. The number of data points replicated with CDC is always lower than its alternative - bulk updates of the entire database. This makes CDC much faster as a replication technique. 
2. Decreased network burden. Sending too much data across different cloud solutions or geographical locations causes delays due to bandwidth-hogging and latency. CDC lowers the volume of transferred data and unburdens the network operations. 
3. Free production resources. CDC is often used to move data from a production database to an analytic database. Because CDC relies on copying data via logs, the replication process does not additionally tap into the limited resources of the production database. Read more about log-based replication here. 
4. Synchronous replication. Because CDC taps into transaction logs to replicate databases, CDC can be used for real-time data replication. CDC supports streaming ETL pipelines and real-time analytics is achievable via CDC.
   

Dive deeper into how CDC achieves the multiple benefits for data operations with our in-depth guide.

One question remains unanswered, though. Why would you need a CDC tool to achieve CDC replication? Couldn’t you build it yourself?

Why do you need a CDC tool?

Of course, you could build a CDC solution in-house. But there are several shortcomings to the homegrown approach:

1. Developer bandwidth. Developers are usually already burdened under a backlog of requests. Building a custom CDC solution would either take a lower priority or detract from existing revenue-generating projects. 
2. Maintenance cost. Writing the script is just the first step. You also need to maintain the custom solution as database schemas and logs change.
3. Implementational challenges. CDC replication is not a weekend project. Due to the differences between database vendors, different log formats, or even hiccups to log access, CDC can be a technical challenge to pull off.
   

Instead of diluting your limited engineering resources further, rely on a tool to do the heavy lifting for you.

The 7 best CDC tools of 2021

CDC Tool #1: Keboola

Keboola is an end-to-end data operation platform offering out-of-the-box features for a variety of data ops:

• CDC data integration. Keboola offers over 250 connectors integrating data sources and destinations. From SaaS applications to data warehouses, extract, transform, load, and replicate your data from a wide variety of data sources.
• Straight-forward visual interface. All operations can be performed with a couple of clicks without the need to write scripts.
• Cloud, on-premise, and hybrid ready. Replicate data bi-directionally across native cloud solutions and on-premise or within the same environment.
• Compliance. With the wide range of monitoring and logging abilities that come with Keboola, all your data events are inspectable and traceable. All the data movements and storage are executed at enterprise-level quality, offering the highest levels of regulatory compliance with all the important regulations, such as GDPR or SOC.
• A multitude of analytic tools. Keboola does not just replicate data, it also assists you with building your ETL data pipelines end-to-end. Push your data into BI tools - such as Looker - or machine learning tools - such as Jupyter Notebooks or devoted experimentation Sandboxes.
  

Discover all Keboola has to offer with its always free tier. Yes, that is correct, Keboola does not offer just a free trial, it offers an always-free account for all your data needs.

CDC Tool #2: Oracle GoldenGate

Oracle GoldenGate uses CDC replication across multitudes of sources enabling real-time analysis. 

Primarily it is designed to replicate Oracle Database with optimized high-speed data movement. But it can also be used to replicate a range of sources, such as Microsoft SQL Server, IBM DB2, Teradata, MongoDB, MySQL, PostgreSQL, HDFS, Kafka, Spark, and cloud object stores across cloud providers.

Alongside data replication, Oracle GoldenGate is also used for end-to-end monitoring of stream data processing solutions without the need to allocate or manage compute environments.

CDC Tool #3: Qlik Replicate

Qlik Replicate, formerly known as Attunity Replicate, is a data ingestion, replication, and streaming tool. 
Qlik Replicate uses parallel threading to process Big Data loads, making it a viable candidate for Big Data analytics and integrations. 

Qlik Replicate integrates data across the major data solutions: from RDBMS (PostgreSQL, MySQL, Oracle, DB2, …), data warehouses, to cloud vendors (AWS, GCP, Azure). 

CDC Tool #4: IBM InfoSphere Change Data Capture

IBM InfoSphere Change Data Capture is a replication solution that uses CDC to replicate data across target databases, messages queues, or ETL solutions such as IBM InfoSphere DataStage. 

Though IBM InfoSphere Change Data Capture connects to multiple data sources, it is best tailored to the suite of IBM data products, such as IBM Db2 databases, IBM Cognos, or IBM Informix databases.

CDC Tool #5: HVR

HVR is a database integration software replicating data across 40 sources and targets. 

It mainly focuses on SAP technologies but can be used for high-volume replication of more classic data products as well, offering data integration across cloud providers (AWS, Azure, GCP) and data warehouses/lakes such as Snowflake. 

CDC Tool #6: Hevo Data Platform

Hevo Data Platform offers CDC replication out of the box through no-code data pipelines.  Its main purpose is to integrate data from a multitude of sources into your data warehouse.

Hevo’s user-friendliness is high, but it comes at the expense of inferior monitoring abilities, and fewer customization features - what you see is what you get.

CDC Tool #7: Talend Data Integration

Talend Data Integration is the enterprise-class open source CDC replication software. Talend offers connections and replications across a myriad of data source types within its easy-to-use interface. 

Though Talend Data Integration is extremely powerful as a CDC tool, it lacks version control as one of the features and it is definitely geared more towards huge enterprises.

Which CDC tool should you pick?

The ultimate tool decision will depend heavily on your specific use case.

Ask yourself these questions when choosing the best CDC tool for your company:

1. What is the total cost of ownership? This includes tool pricing, but also hosting, onboarding, and learning the tool, and maintenance fees or customization fees.
2. Who will use the tool? If the tool is targeted towards engineers, it has to have a code-pen or programmatic access. If you envision non-technical people using the tool, choose the one with a user-friendly and intuitive UI.
3. Does the tool cover all of my main use cases? Just the main ones? Check which integrations are available. Is your database supported by the vendor? Do you envision extracting data from a Third-Party App that is not on the tool’s list of supported apps?
   

Go through the list of top CDC tools and mark them against these criteria.

Then compare it to Keboola:

• It integrates with over 250 sources and destinations. 
• It has a generic connector, allowing you to replicate data from apps not yet covered with a devoted connector.
• It is extremely user-friendly, while it also allows your engineers to play with the nuts and bolts. 
• It has a free tier. Seriously, try it out yourself.

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