From the objective of OSS-DB Exam Silver
- Operation management - backup method
Sample Question
1.41
Choose two correct answers from the below explanations about backups using the pg_basebackup command.
- Use the pg_restore command to restore.
- Stop the database before creating the backup.
- It can be used as a base backup for point-in-time recovery (PITR).
- It can be used as a base backup for replication.
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You can get backups on a per-database basis.
※This sample exam is different from those that appear in the actual OSS-DB Exam.
2019/05/27
Answer and Explanation
The procedure for acquiring the base backup for point-in-time recovery (PITR)
(1) Connect to the database with super user authority,
Execute SELECT pg_start_backup ('some label');
(2) Obtain a physical copy (base backup) of the entire database cluster without stopping the database
(3) Connect to the database with super user authority,
SELECT pg_stop_backup (); will be executed, but by using the new pg_basebackup command in PostgreSQL 9.1, you can execute these procedures collectively. In addition to PITR, the created base backup can also be used for streaming replication.
Since pg_restore is a command to restore a backup created by pg_dump, it can not be applied to the base backup created by pg_basebackup. In addition, base backups are created for the entire database cluster and can not be acquired for individual databases in the cluster.
Therefore, the correct answers are C and D.