Definition - What does Transactional Replication mean?
Transactional replication is the automated periodic distribution of changes between databases. Data is copied in (or near) real-time from the primary server (publisher) to the receiving database (subscriber). Thus, transactional replication offers an excellent backup for frequent, daily databases changes.
Techopedia explains Transactional Replication
In most cases, transactional replication begins by taking a publisher snapshot, which is then copied to the subscriber. Then, any publisher changes are logged in real-time and replicated at the subscriber.
Transactional replication does not simply copy the net effect of data changes, but rather consistently and accurately replicates each change.
For example, a customer’s account balance in a commercial bank’s publisher database initially reads $2,000. Then, within the span of a few minutes, the customer deposits $500 and then withdraws $1000 from the ATM. The net effect is $2000+$500-$1000=$1500. However, a transactional replication does not simply update the subscriber client account as $1500. Each of these two transactions also must be written to the subscriber.
Because of its near real-time nature, transactional replication is frequently used by two or more database administrators (DBAs) as a failover mechanism where more than a few minutes of downtime is not an option, e.g. ATM networks and nuclear power stations. In this regard, transactional replication has proven to be a reliable mechanism for backup databases.
Other replication types include merge and snapshot replication.