Backup and Restore

Database Backup

Machbase’s database backup is classified as follows, and either backup of the entire database or backup of the specific table is possible.

• Full backup: Backup of entire data
• Incremental backup: Backup of the data added after the full or previous incremental backup
• Duration backup: Backup of data for a specific period

Syntax:

# Full backup
BACKUP [ DATABASE | TABLE table_name ]  INTO [ DISK ] = 'path/backup_name';
time_duration = FROM start_time TO end_time

# Incremental backup
BACKUP [ DATABASE | TABLE table_name ] AFTER 'previous_backup_dir' INTO [ DISK ] = 'path/backup_name';

# Duration backup
BACKUP [ DATABASE | TABLE table_name ]  [ time_duration ] INTO [ DISK ] = 'path/backup_name';

Absolute and relative path can be used for path. set start time and end time of backup data for time_duration.

Example:

-- Full backup backup
BACKUP DATABASE INTO DISK = 'backup_dir_name';

-- Incremental backup
BACKUP DATABASE INTO DISK = 'previous_backup_dir' INTO DISK = 'path/backup_name';

-- Time range backup
BACKUP DATABASE FROM TO_DATE('2015-07-14 00:00:00','YYYY-MM-DD HH24:MI:SS')
                TO TO_DATE('2015-07-14 23:59:59','YYYY-MM-DD HH24:MI:SS')
                INTO DISK = '/home/machbase/backup_20150714'

When executing the backup command, the backup type and backup destination path must be defined. To back up the entire database, you must specify “DATABASE”. To back up specific tables, specify “TABLE” as the backup type. When backing up specific tables, you must specify the table name.

You can specify the backup destination using the time_duration clause. Specify the start time and end time of the backup target data in the FROM and TO clauses. In the example above, “2015-07-14 00:00:00” is defined as FROM and “2015-07-14 23:59:59” is defined as TO, so the user will be able to see all data for July 14, 2015 Quot; Duration If you do not specify a time condition, “1970-01-01 00:00:00” is set to FROM and the current time at which it is executed is set in the TO clause.

Note that when specifying a backup path, backup files are created under “$ MACHBASE_HOME / dbs” when a relative path is specified. To specify an absolute path, you must always set a path that starts with “/”.

Database Restore

Data can be restored from the backup files with the following constraints.

• Cannot be executed via query commands(can only be performed using the ‘machadmin’ command.)
• The database must be in a stopped state.
• The current data will be deleted after restore(confirmation is required to ensure that the current data are not used any longer).
• For incremental backup, previous full and incremental backup files are required.
• In case of tag table, restoration of time range backup is not supported.

Syntax:

machadmin -r backup_database_path

Example:

backup database into disk = '/home/machbase/backup';

machadmin -k
machadmin -d
machadmin -r /home/machbase/backup;