You can obtain a base backup of a PostgreSQL database cluster running on a separate server.
The pg_start_backup command must be executed before the pg_basebackup command is executed.
In the case of fetch method, the max_wal_senders parameter should be set to at least 1.
WAL is included in the backup if the command is executed without explicitly specifying options.
If an additional tablespace is created, the data within the tablespace is not included in the backup.
※This sample exam is different from those that appear in the actual OSS-DB Exam.
2025/05/29
[Option A]
Replication protocols are used for backups, and base backups can be obtained from another server running remotely.
[Option B]
The pg_basebackup command automatically handles the execution of pg_start_backup, the transfer of data within the database cluster, and the execution of pg_stop_backup. Therefore, it is unnecessary to execute pg_start_backup beforehand.
[Option C]
At least one max_wal_senders is required for backups using the fetch method, and two slots are used with the stream method. In practice, the value of max_wal_senders should be set high enough to accommodate other replication connections, etc.
[Option D]
WAL is included in the backup even when executed without explicitly specifying options like -x.
[Option E]
Even if additional tablespaces have been created, backups can be taken that include data within those tablespaces.
Therefore, statements B and E are not accurate.
Refer to the official documentation for details. (Please note that there are parts of the specifications that differ depending on the Version.)
https://www.postgresql.org/docs/10/app-pgbasebackup.html
The correct answers are B and E.