Why use replication? v7
You can use data replication in a variety of use cases in organizations where it's important to use the same data in multiple settings. This replication of data allows users to work with real data that yields real results that are reliable in more than one setting. Support of both single-master and multi-master replication gives Replication Server a broad range of supported use cases.
In this use case, users take all or a subset of data from a production OLTP system and replicate it to another database whose sole purpose is to support reporting queries. This approach can have multiple benefits:
- Reporting loads are removed from the OLTP system, improving transaction processing performance.
- Query performance improves without being subordinated to transactions on the system.
- In Oracle installations, the reporting server duties can be handled by a product like EDB Postgres Advanced Server, reducing licensing costs for a reporting server.
When organizations want to improve the availability of their data, one cost-effective solution is to use warm standby servers. These are database servers kept up to date with the online system through replication. You can bring these servers online quickly when a failure occurs in the production system. You can also use warm standby servers for regular maintenance by switching over to the standby server so that you can take the production server offline for regular maintenance.
Upgrading or moving to a new database system sometimes requires that the old and new systems be up and running in parallel to allow for testing and comparing results in real time. You can use replication in this use case. It's frequently used in development and testing environments.
Similar to running in parallel is the situation in which you migrate data from one system to another in a sort of seeding operation. Replication can be very effective in this situation by quickly copying data.
In single-master replication, only the primary database is available for writes. The secondary databases are read-only for applications. If the replicated target databases must be available for write access as well, you can use multi-master replication for the same use cases as single-master replication but with the additional advantage of write access to the secondary.
In write-intensive applications, multi-master replication allows you to use multiple database servers on separate hosts to process write transactions independently of each other on their own primary databases. You can then reconcile changes across primary databases on your own schedule.
In a geographically dispersed application, you can provide local access to the database to regions of clients. Having the database servers physically close to clients can reduce latency with the database. Multi-master replication allows you to use a WAN-connected network of primary databases that can be geographically close to groups of clients yet maintain data consistency across primary databases.