Session I/O Interval (PI_PIIO)
- Organization of this page
Function
The Session I/O Interval (PI_PIIO) record stores performance data, taken at specific intervals, about input/output of all active sessions. PFM - Agent for Oracle creates one record for each active session. This is a multi-instance record.
Note that this record is valid if PFM - Agent for Oracle monitors information about a session whose connection continues for a long time in the Oracle database being monitored. A session of a connection pool is an example of such a session. However, valid data cannot be retrieved when connection and disconnection take place repeatedly because the ODBC key field is PI_PIIO_SID. In this case, when the difference from the previous value is retrieved for a delta, a possibility of retrieving the difference from a different session exists.
- Notes
-
If the monitoring target is Oracle Database 12c Release 2 or later in a CDB configuration, this record includes I/O information about active sessions of the PDBs that are being monitored, and about common active sessions of database instances.
Default and changeable values
|
Item |
Default value |
Changeable |
|---|---|---|
|
Collection Interval |
300 |
Y |
|
Collection Offset |
25 |
Y |
|
Log |
No |
Y |
|
LOGIF |
(Blank) |
Y |
|
Over 10 Sec Collection Time |
No |
N |
ODBC key fields
PI_PIIO_SID
Lifetime
From the start to the end of a session
Record size
-
Fixed part: 678 bytes
-
Variable part: 186 bytes
Fields
|
PFM - View name (PFM - Manager name) |
Description |
Summary |
Format |
Delta |
Supported version |
Data source |
|---|---|---|---|---|---|---|
|
Block Changes (BLOCK_CHANGES) |
Number of times changes were made to session blocks#2 |
AVG |
double |
Yes |
All |
V$SESS_IO.BLOCK_CHANGES |
|
Block Gets (BLOCK_GETS) |
Number of times session blocks were acquired#2 |
AVG |
double |
Yes |
All |
V$SESS_IO.BLOCK_GETS |
|
Cache Hit % (CACHE_HIT_PERCENTAGE) |
Buffer cache usage#2 |
AVG |
double |
No |
All |
100 * (BLOCK_GETS + CONSISTENT_GETS - PHYSICAL_READS) / (BLOCK_GETS + CONSISTENT_GETS) |
|
Consistent Changes (CONSISTENT_CHANGES) |
Number of times a consistent change was made in the session#2 |
AVG |
double |
Yes |
All |
V$SESS_IO.CONSISTENT_CHANGES |
|
Consistent Gets (CONSISTENT_GETS) |
Number of times a consistent acquisition was made in the session#2 |
AVG |
double |
Yes |
All |
V$SESS_IO.CONSISTENT_GETS |
|
OS PID (PID) |
Client process ID of the OS#1 |
COPY |
string(30) |
No |
All |
V$SESSION.PROCESS |
|
Physical Reads (PHYSICAL_READS) |
Number of physical read operations in the session#2 |
AVG |
double |
Yes |
All |
V$SESS_IO.PHYSICAL_READS |
|
Record Time (RECORD_TIME) |
Collection termination time for the performance data stored in the record#1 |
COPY |
time_t |
No |
All |
Agent Collector |
|
Record Type (INPUT_RECORD_TYPE) |
Record name (always PIIO)#1 |
COPY |
string(4) |
No |
All |
Agent Collector |
|
SID (SID) |
Session ID#1 |
COPY |
ulong |
No |
All |
V$SESS_IO.SID |
|
Start Time (START_TIME) |
Collection start time for the performance data stored in the record#1 |
COPY |
time_t |
No |
All |
Agent Collector |
|
User (USERNAME) |
User name of the session#1 |
COPY |
string(30) |
No |
All |
V$SESSION.USERNAME |