Sample Exam Questions

From the objective of OSS-DB Exam Silver
S3.1 SQL commands (Replication)

Sample Question


Choose three appropriate descriptions for logical replication.

  1. It can replicate on a per-database basis.

  2. It can replicate on a per-table basis.

  3. All DDL commands are replicated.

  4. It can be used to replicate between different major versions.

  5. The tables to be replicated can be updated on the publisher side, but not on the subscriber side.

※This sample exam is different from those that appear in the actual OSS-DB Exam.

Answer and Explanation

Streaming replication and logical replication are available as replication features in PostgreSQL.

Logical Replication is a feature added in PostgreSQL version 10. It decodes WAL generated by the publisher (source) and forwards logical changes to the subscriber (destination).

Replication can be performed on a per-database or per-table basis, and only some SQL (INSERT, UPDATE, DELETE, TRUNCATE) is replicated.

DDL commands are not replicated, except for the TRUNCATE command.

It can be replicated across different major versions and is also used to perform major version upgrades.

Data can be updated by either the publisher (source) or the subscriber (destination).

So the correct answers are A, B and D.