Limits on the number of backup devices

When using the BACKUP command of Sybase IQ, users can parallelize the operation to multiple devices by specifying multiple TO clauses. The backup statement has an upper limit of 36 on the device numbers. If the upper limit is exceeded, the statement produces an error.

This limit affects all versions of Sybase Risk Analytics Platform and Sybase RAP - The Trading Edition™.


Corrective actions for future backups

Users must create future backups using 36 or fewer TO clauses in a BACKUP command, a limit that will be enforced in future versions of Sybase IQ.

Keep backup commands small. Do not to go to extremes with the number of devices, as this will cause I/O and hardware contention with more devices. As a practical guideline, use roughly 1 device per core on the machine to saturate CPU usage. Use up to 2 devices per core on faster systems.