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Object documentation PHYSFILE (Informix)  Locate the document in its SAP Library structure

Definition

The PHYSFILE parameter in the Informix ONCONFIG file specifies the size of the physical log file in KB.

The default for new R/3 installations is 20,000 KB.

Use

For up-to-date recommendations, see SAP Note 41360.

This size can influence the checkpoint interval. As soon as the physical log is filled to 75%, a checkpoint is performed. When increasing the CKPTINTVL parameter, check whether you have to adjust the size of the physical log.

If checkpoints are occurring more frequently than the checkpoint interval, you might want to increase the size of the physical log file. You can do this using the Informix ONMONITOR tool.

Caution

Do not change PHYSFILE with the "vi" editor in the ONCONFIG file.

There must be enough contiguous space in the physdbs dbspace to accommodate the new PHYSFILE size.

The formula for the maximum size is:

(20 x connections x page size) / 1024

where:

2048 for HP UX, SINIX, SOLARIS and OSF/1

4096 for AIX and NT

This is the number of processes logged on to the database system, where one process represents one user. Since in an SAP environment, an SAP work process works for several users, it is multiplied in the formula by 20.

 

See also:

CKPTINTVL (Informix)