How does a shared database work?

Question

Use a (single) database that is shared by multiple services. Each service freely accesses data owned by other services using local ACID transactions.

What is a shared database?

A Shared Database allows you to store your documents in your favorite relational (SQL) database rather than on the file system. This means that multiple users can concurrently use the same synchronized storage location without any problems.

Is shared database an Antipattern?

Why a shared database is considered an anti-pattern in the microservice architecture. Data sovereignty is a rule that states that each microservice owns its domain data and logic. Other microservices that wanted to access or modify that data, will need to pass for the microservice itself for doing it.

Can data in a database be shared?

It implies that the data are stored in one or more servers in the network and that there is some software locking mechanism that prevents the same set of data from being changed by two people at the same time. Data sharing is a primary feature of a database management system (DBMS).

In the shared-database-per-service pattern, the same database is shared by several microservices. You need to carefully assess the application architecture before adopting this pattern, and make sure that you avoid hot tables (single tables that are shared among multiple microservices).

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