From the objective of OSS-DB Exam Silver
- Operation and Management - Installation Method (Concept and Structure of Database Cluster)
Sample Question
1.21
Choose the most accurate description about a PostgreSQL database cluster.
- used for high availability, it is a mechanism to duplicate databases across multiple servers.
- Immediately after installation, three databases, template0, template1, and postgres, are provided.
- Only one database cluster can be created on one server.
- Different versions of PostgreSQL server can be used for each database in the database cluster.
※This sample exam is different from those that appear in the actual OSS-DB Exam.
2019/03/04
Answer and Explanation
The database storage area of PostgreSQL contains multiple databases, which are called database clusters. Please note that it does not relate to clustering technology used for high availability.
Immediately after creating the database cluster with the Initdb command, three databases, template0, template1, and postgres, are included.
Since one database cluster is managed by the same server process, multiple databases in the cluster use the same version of PostgreSQL.
It is also possible to create multiple database clusters on one server. In order to run multiple versions of PostgreSQL on a single server, you need to create a separate database cluster for each version.
Therefore, the correct answer is B.