1.1 What’s New
• BART no longer requires the use of the PostgreSQL pg_basebackup utility program to take full base backups from database servers with the exception of standby servers, which does require pg_basebackup. This provides a performance improvement for taking full backups as described by the next point.
• Full backups can now be taken using multiple, parallel worker threads, thus reducing the backup time. The number of worker threads is specified by the BACKUP subcommand --thread-count option (see Section 5.4.3), or by the thread_count parameter in the BART configuration file (see sections 4.1 and 4.2.5). The multiple processes are also used for the compression operation when taking full backups with the BACKUP subcommand -z or -c options to provide parallel, compressed tar backups.
• BART takes full backups from standby servers using the pg_basebackup utility program. Note that incremental backups cannot be taken from standby servers.
• The BACKUP subcommand now supports the --with-pg_basebackup option, which forces the use of pg_basebackup for taking a full backup.
• The BACKUP subcommand now supports the --no-pg_basebackup option, which prevents the use of pg_basebackup for taking a full backup except for standby servers. Instead, the worker thread process is used as previously described by the second bullet point.
• Restoring incremental backups can now be done with a specified number of parallel worker processes using the RESTORE subcommand with the -w option. Previously only a single worker process was used. This provides quicker restore times for incremental backups. For more information, see Section 5.4.8.
• The BART configuration file now contains the scan_interval parameter, which specifies the number of seconds before a forced scan of the WAL files will occur. By default, the BART scanner program would scan the archived WAL files only if their presence had been detected, which might result in missing the scanning, and thus, result in the absence of required MBM files. The scan_interval parameter can now be used to force the scanning. See Section 5.5 for information on the BART scanner. See sections 4.1 and 4.2.5 for the scan_interval parameter.