Oracle Server Manager User's Guide

The System I/O Monitor

The System I/O Monitor displays the percentage of input/output activity generated by background and user processes accessing the database. The statistics shown are relative distributions among the processes, not precise counts of I/O operations.

The following figure illustrates the left-most columns of the System I/O Monitor.

Figure 11 - 13. System I/O Monitor

The System I/O Monitor is described below:

Process ID Oracle process identifier.
Session ID Session identifier.
System Username Username associated with the system process.
Change in % logical reads Change in the percentage logical reads for the process since the last sample.
Change in % physical reads Change in the percentage physical reads for the process since the last sample.
Change in % logical writes Change in the percentage logical writes for the process since the last sample.
Total % logical reads Logical reads for the process as a percentage of all logical reads since startup.
Total % physical reads Physical reads for the process as a percentage of all physical reads since startup.
Total % logical writes Logical writes for the process as a percentage of all logical writes since startup.

Attention: In the System I/O Monitor you can only sort on the Process ID, Session ID, and System Username columns.

SQL Worksheet Equivalent

To start the System I/O Monitor from a SQL Worksheet, you can use the following Server Manager commands:

	MONITOR SYSTEMI/O

	MONITOR SIO

Required Views

To use the System I/O Monitor, you must have access to:

V$PROCESS

V$SESSION

V$SESS_IO

Process ID	Oracle process identifier.
Session ID	Session identifier.
System Username	Username associated with the system process.
Change in % logical reads	Change in the percentage logical reads for the process since the last sample.
Change in % physical reads	Change in the percentage physical reads for the process since the last sample.
Change in % logical writes	Change in the percentage logical writes for the process since the last sample.
Total % logical reads	Logical reads for the process as a percentage of all logical reads since startup.
Total % physical reads	Physical reads for the process as a percentage of all physical reads since startup.
Total % logical writes	Logical writes for the process as a percentage of all logical writes since startup.