Sample Exam Questions

From the objective of OSS-DB Exam Silver
- Operation management - backup method

Sample Question

1.52

Choose the correct statement for performing a point-in-time recovery (PITR) base backup.

  1. Execute the pg_dump command
  2. Execute the pg_dumpall command

  3. Connect to the database with psql and execute the COPY command
  4. Stop the database and copy the whole database cluster using a command attached to the OS, such as the tar command

  5. Use pg_start_backup and pg_stop_backup with a copy of the entire database cluster using the tar command. 

※This sample exam is different from those that appear in the actual OSS-DB Exam.
2019/05/30

Answer and Explanation

Database backups are one of the most important considerations in operational management.

In PostgreSQL, pg_dump and pg_dumpall commands produce logical backups of the database, multiple backups such as cold backup (directory copy) that physically copies the whole database cluster and PITR that enables recovery of data update after backup are available.

PITR creates a base backup by physically copying the entire database cluster using commands such as tar, but at this time, unlike cold backup, the database itself is not stopped. Instead, connect to the database as an administrator user before and after the backup and by executing the following command.

SELECT pg_start_backup ('some label');

SELECT pg_stop_backup ();

 

Therefore, the correct answer is E.