i/o accounting flush interval

i/o accounting flush interval specifies the amount of time, in machine clock ticks, that SAP ASE waits before flushing I/O statistics for each user from sysprocesses to syslogins. This is used for charge-back accounting.

When a user logs in to SAP ASE, the server begins accumulating I/O statistics for that user process in sysprocesses. When the value of i/o accounting statistics interval is exceeded, or a user logs off SAP ASE, the accumulated I/O statistics for that user are flushed from sysprocesses to syslogins. These statistics continue accumulating in syslogins until you clear the totals by using sp_clearstats. You can display the current totals from syslogins by using sp_reportstats.

The value to which you set i/o accounting flush interval depends on the type of reporting you intend to do. If you run reports on a monthly basis, set i/o accounting flush interval to a relatively high value. With infrequent reporting, it is less critical that the data in syslogins be updated frequently.

If you perform periodic ad hoc selects on the totio column syslogins to determine I/O volume by process, set i/o accounting flush interval to a lower value. Doing so increases the likelihood of the data in syslogins being current when you execute your selects.

If you do not report on I/O statistics at all, set i/o accounting flush interval to its maximum value. This reduces the number of times syslogins is updated and the number of times its pages must be written to disk.