The desired backup acquisition mode can be selected by specifying the -M option of the database copy utility (pdcopy command). Table 6-1 lists the backup acquisition modes.
Table 6-1 Backup acquisition modes
Backup acquisition mode (-M option specification) | Description of mode | Point to which RDAREAs can be restored |
---|---|---|
Referencing/updating-impossible mode (x) | RDAREAs being backed up cannot be referenced or updated while the backup is being made. Subject RDAREAs must be placed in shutdown and closed status with the pdhold -c command before the backup is made. | Using a backup made in this mode, the database can be restored to the point when the backup was made. If a system log is used, the database can be restored to any synchronization point after the backup was made. |
Referencing-permitted mode (r) | RDAREAs being backed up can only be referenced during backup processing; they cannot be updated. | |
Updatable mode (s)1 | RDAREAs being backed up can be referenced and updated during backup processing. | A database cannot be restored to the point when the backup was made. It can be restored only to a synchronization point subsequent to the point when the backup was made. Therefore, database restoration requires both the backup and the system log2 from a synchronization point immediately prior to when the backup was made. |
The backup acquisition mode that can be specified for backup processing depends on the database update log acquisition mode, as shown in Table 6-2. For details on the database update log acquisition mode, see 7. Operation Without Acquiring a Database Update Log.
Table 6-2 Backup acquisition mode depending on the database update log acquisition mode
Database update log acquisition mode | Specifiable backup acquisition mode (-M option specification) |
---|---|
Log acquisition mode | Referencing/updating-impossible mode (x) Referencing-permitted mode (r) Updatable mode (s) |
Pre-update log acquisition mode | Referencing/updating-impossible mode (x) Referencing-permitted mode (r) |
No-log mode |