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How Does Real-Time Data Replication Work?

In today’s world – where data is produced in greater amounts and at higher frequencies than ever before – it’s crucial for businesses to keep their data up to date.

That’s complicated enough when data is being produced and maintained within a single system. But maintaining up-to-date data is even more complex when data is distributed to multiple sources.

This is a challenge. But, with the right approach and the right tools, it’s solvable.

Let’s take a look at how real-time data replication works.

The Definition of Real-Time Data Replication

At a bottom-line level, real-time data replication means that, when data from the replicated database is accessed, it is an up-to-date copy of the data. The replicated database queries return the same results as if they were run on the source database. Note that real-time data replication does not mean that data is literally replicated at the same time it’s published; there will be some delay, however slight.

To illustrate: Let’s say that an enterprise has a database of transaction data that’s being replicated for access by the customer service team. When a customer calls in with a question and the customer service rep checks the server where data is being replicated, they should see the customer’s data as it’s represented in the publisher. In other words, the customer service rep shouldn’t have the wrong information.

Or, in another example: Many customers choose to move transaction-heavy applications such as an airline reservation system to a replicated database to reduce latency and free up production resources. Neither system can afford to have changes captured in one database and not in another; that leads to double bookings and ruined schedules. Real-time data replication means that when data is accessed from the replicated database, it will always show the updated flight information.

This means that, practically, the need for “real-time” replication is dependent on how often data needs to be accessed. If you’re using data replication for an end-of-day reporting application, for example, then you might tolerate some latency; instead of real-time replication, you could choose to use snapshot replication to get accurate data once per day at the close of business.

Transactional Replication: The Most Common Method of Real-Time Replication

“Real-time” replication refers to replication that takes a transactional approach to capturing change data.

In transactional replication, changes to records are updated in the destination databases as soon as they’re made in the source databases. Instead of moving the entire dataset over at regular intervals and then comparing any changes, transactional replication moves only the data that has been changed.

There are a few technical approaches to enacting transactional replication, but the most common (and, typically, the best) is to use log-based change data capture.

How Log-Based Replication Works

Most modern database management systems have built-in change logs that are actually outside of production resources; logs are a fundamental design principle to ensure forward recovery or rollback of transactions that weren’t completed. The benefit of logs in data replication is that accessing them represents a near-zero impact on the production database.

Additionally, this mode of replication is highly accurate.

How Tools Make Real-Time Data Replication Possible

If you’re looking to enact accurate real-time data replication, then, your best bet is to use a tool that takes a transactional replication approach using log-based change data capture.

Our data replication software, StarQuest Data Replicator (SQDR), is designed to facilitate exactly this approach.

SQDR scrapes database logs and converts data into a canonical source, so that it can be easily distributed to heterogeneous or homogenous databases. The software sits between the source and destination databases, causing virtually zero impact on production capacity. Any changes in the logs are published immediately to any number of destination databases.

The end result is that SQDR makes real-time data replication easy, even when replicating between different database types.

Ready to Implement a Real-Time Data Replication Solution?

Hopefully, the information above has helped you to further understand the process of data replication and to identify what “real-time” replication might mean in your business context.

If you’re ready to move forward with a real-time data replication solution to keep data current in distributed systems, get in touch with us.

At StarQuest, we’re experts at data replication. As described above, our powerful SQDR software can be utilized for replication from an extensive range of data sources.

And, importantly, our customer service team is regarded as some of the best in the business, with clients calling us “The best vendor support I have ever encountered.”

Get in touch with us to discuss your data replication needs. We can set you up with a no-charge trial of our software using the DBMS of your choice, and help you take the first step toward a real-time data replication solution that will keep your systems up to date.