Physical Log

The physical log contains before-images of pages (units of storage) changed since the last checkpoint. The physical log combines with the logical log to allow fast recovery from a system failure. Use the following parameters to describe the physical log.

Configuration
Parameter

Description

PHYSBUFF

Determines the amount of shared memory reserved for a buffer of before-images destined for the physical log on disk.

PHYSDBS

Specifies the name of the dbspace in which the physical log resides on each coserver. The maximum length of PHYSDBS is 128 characters.

Any occurrence of the PHYSDBS parameter overrides the PHYSSLICE parameter for a particular coserver specified in the ONCONFIG file.

PHYSFILE

Specifies the size of the physical log.

You can specify a coserver-specific PHYSFILE parameter if you want a different physical log size for a specific coserver.

PHYSSLICE

Each coserver has one physical log file. PHYSSLICE specifies the name of the dbslice that contains the physical log. The maximum length of PHYSSLICE is 128 characters. You cannot specify PHYSSLICE in the coserver-specific section of the ONCONFIG file.

For more information, see Physical Logging.