Polyglot persistence

This refers to the system that uses different databases for each of its components. The idea is to choose the database that best fits the needs for a particular component.

The flexibility of RDBMS have led to a scenario where over the years, it has become a default choice for persistence. In some cases, RDBMS is severely constraining and we have been addressing it by having a layer of abstraction on top of the RDBMS solution. Some examples of the abstractions that we have used are

• Having a caching layer that reads from the database
• Storing files as byte arrays and having functions that converts files to byte arrays & back
• Building data access layer to map complex object to relational model

The emergence of different varieties of NoSQL databases has given us the choice to choose from a wide variety of options.

A complex enterprise application comes with multiple modules & functionalities, all its data needs may not be met with a single persistence technology. It would be beneficial to pick the right database for each.

The solution that includes multiple databases for its persistence needs is referred to as polyglot persistence

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