Session Statistics Summary (PD_PDS2)
- Organization of this page
Function
The Session Statistics Summary (PD_PDS2) record stores performance data indicating the status (at a specific point in time) of each session and performance indicator of an instance. PFM - RM for Oracle create one record for each session in an instance. This is a multi-instance record.
If you cannot view the performance data in this record, create Oracle's static data dictionary view DBA_WAITERS. To create the static dictionary view DBA_WAITERS, you need to execute the CATBLOCK.SQL script that is provided by Oracle.
- Notes
-
If the monitoring target is Oracle Database 12c Release 2 or later in a CDB configuration, this record includes information about sessions and performance indicators of the PDBs that are being monitored, and about common sessions and performance indicators of database instances.
Default and changeable values
|
Item |
Default value |
Changeable |
|---|---|---|
|
Collection Interval |
600 |
Y |
|
Collection Offset |
105 |
Y |
|
Log |
No |
Y |
|
LOGIF |
(Blank) |
Y |
|
Over 10 Sec Collection Time |
No |
N |
ODBC key fields
PD_PDS2_SID
Lifetime
From the start to the end of a session
Record size
-
Fixed part: 935 bytes
-
Variable part: 412 bytes
Fields
|
PFM - View name (PFM - Manager name) |
Description |
Summary |
Format |
Delta |
Supported version |
Data source |
|---|---|---|---|---|---|---|
|
Block Changes/Tran (BLOCK_CHANGES_PER_TRANSACTION) |
Rate at which each transaction executed DML operation |
-- |
double |
No |
All |
db block changes / user commits |
|
Block Visits/Tran (BLOCK_VISITS_PER_TRANSACTION) |
Number of work database read operations executed per transaction |
-- |
double |
No |
All |
(db block gets + consistent gets) / user commits |
|
Blocking Locks (BLOCKING_LOCKS) |
Number of locks owned by the session that are blocking another lock Correct values cannot be collected in this field, and 0 is always displayed. |
-- |
double |
No |
All |
Remote Monitor Collector |
|
Cache Hit % (CACHE_HIT_PERCENTAGE) |
Buffer cache usage |
-- |
double |
No |
All |
(1 - (physical reads cache / (consistent gets from cache + db block gets from cache))) * 100 |
|
Calls/Tran (CALLS_PER_TRANSACTION) |
Rate at which client requests were executed per transaction |
-- |
double |
No |
All |
user calls / user commits |
|
Changed Block % (CHANGED_BLOCK_PERCENTAGE) |
Percentage indicating the balance between queries and DML in the database application. This value changes according to indexes and application utilization status. |
-- |
double |
No |
All |
(db block changes / (block gets + consistent gets)) * 100 |
|
Consistent Change % (CONSISTENT_CHANGE_PERCENTAGE) |
Percentage indicating the extents for which the application needed to check the consistency of read operations |
-- |
double |
No |
All |
(consistent changes / consistent gets) * 100 |
|
Continued Row % (CONTINUED_ROW_PERCENTAGE) |
Percentage ratio of rows obtained that were longer than one block or had been moved |
-- |
double |
No |
All |
(table fetch continued row / (table fetch by rowid + table scan rows gotten)) * 100 |
|
Deadlocks (LOCK_DEADLOCKS) |
Number of process deadlocks caused by enqueuing (locking) of DML processing |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Disk Sorts (SORTS_DISK) |
Number of disk sort operations |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Lock Conversions (LOCK_CONVERSIONS) |
Number of enqueues (locks) whose mode was changed (such as from share to lock) |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Lock Releases (LOCK_RELEASES) |
Number of times enqueuing (locking) was released. This statistical information is the same as the number of lock requests. |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
|
Lock Requests (LOCK_REQUESTS) |
Number of times enqueuing (locking) was requested |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Lock Timeouts (LOCK_TIMEOUTS) |
Number of times enqueuing (locking) request was not permitted within the specified wait time |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Lock Waits (LOCK_WAITS) |
Number of times the lock request was placed in wait status. The number of lock requests that were not placed in wait status is obtained by subtracting the number of enqueued waits from the number of lock requests. |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Logical Reads (LOGICAL_READS) |
Sum of the number of logical read operations in read consistency mode and the number of requests to the current copy of block |
-- |
double |
No |
All |
db block gets + consistent gets |
|
Memory Sorts (SORTS_MEMORY) |
Number of sort operations in memory |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Non-Index Lookups % (NON_INDEX_LOOKUPS) |
Percentage ratio of full table scans that do not involve caching |
-- |
double |
No |
All |
(table scans (long tables) / (table scans (short tables) + table scans (long tables))) * 100 |
|
PGA Memory (PGA_MEMORY) |
Size of PGA memory in use during data collection |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Physical Writes (PHYSICAL_WRITES) |
Number of physical write operations on the disk by DBWR |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Physical Reads (PHYSICAL_READS) |
Number of times a database block was actually read from disk |
-- |
double |
No |
All |
physical reads - physical reads direct - physical reads direct (lob) |
|
Program (PROGRAM) |
Program name of OS |
-- |
string(48) |
No |
All |
V$SESSION.PROGRAM |
|
Record Time (RECORD_TIME) |
Collection termination time for the performance data stored in the record |
-- |
time_t |
No |
All |
Remote Monitor Collector |
|
Record Type (INPUT_RECORD_TYPE) |
Record name (always PDS2) |
-- |
string(4) |
No |
All |
Remote Monitor Collector |
|
Recursive Calls (RECURSIVE_CALLS) |
Number of user calls processed |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Recursive to User Call % (RECURSIVE_TO_USER_CALL_PERCENTAGE) |
Correct values cannot be collected in this field. Percentage indicating overhead. |
-- |
double |
No |
All |
(recursive calls / user calls) * 100 |
|
Redo Log Space Requests (REDO_LOG_SPACE_REQUESTS) |
Number of times Oracle must wait until disk space is allocated for the REDO log entry, because the active log file is full |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Redo Log Space Wait % (REDO_LOG_SPACE_WAIT_PERCENTAGE) |
Percentage of waiting time until disk space is allocated for the REDO log entry |
-- |
double |
No |
All |
(redo log space requests / redo entries) * 100 |
|
Row Source % (ROW_SOURCE_PERCENTAGE) |
Percentage ratio of all rows obtained by full table scan |
-- |
double |
No |
All |
(table scan rows gotten / (table fetch by rowid + table scan rows gotten)) * 100 |
|
SID (SID) |
Session ID |
-- |
ulong |
No |
All |
V$SESSION.SID |
|
SQL Net Bytes Rcvd (SQL_NET_BYTES_RECEIVED) |
Number of bytes received from clients via SQL*Net |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
SQL Net Bytes Sent (SQL_NET_BYTES_SENT) |
Number of bytes sent to clients via SQL*Net |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Session Cursor Cache Count (SESSION_CURSOR_CACHE_COUNT) |
Total number of references to the cursor |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Session Cursor Cache Hit % (SESSION_CURSOR_CACHE_HIT_PERCENTAGE) |
Number of times an access to the session cursor was executed but the session cursor was not found in the cache |
-- |
double |
No |
All |
(session cursor cache hits / session cursor cache count) * 100 |
|
Session Cursor Cache Hits (SESSION_CURSOR_CACHE_HITS) |
Recorded count of session cursor cache hits |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
Sort Overflow % (SORT_OVERFLOW_PERCENTAGE) |
Percentage ratio of sort operations using temporary segments |
-- |
double |
No |
All |
(sorts (disk) / (sorts (memory) + sorts (disk))) * 100 |
|
Start Time (START_TIME) |
Collection start time for the performance data stored in the record |
-- |
time_t |
No |
All |
Remote Monitor Collector |
|
Statement CPU (STATEMENT_CPU) |
Total CPU time used by active statements during data collection. In centiseconds (1/100 of a second). To collect the value of this field, the TIMED_STATISTICS parameter must be set to TRUE in the init.ora file. |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
UGA Memory (UGA_MEMORY) |
Number of session memory segments used |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
User (USERNAME) |
Oracle user name |
-- |
string(30) |
No |
All |
V$SESSION.USERNAME |
|
User Calls (USER_CALLS) |
Number of user calls processed by active sessions |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
User Calls / Parse (USER_CALLS_PER_PARSE) |
Percentage indicating how well the application is managing the context area |
-- |
double |
No |
All |
user calls / parse count (total) |
|
User Commits (USER_COMMITS) |
Number of transactions |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
User Rollback % (USER_ROLLBACK_PERCENTAGE) |
Percentage ratio of application transactions that failed (rolled back) |
-- |
double |
No |
All |
(user rollbacks / (user commits + user rollbacks)) * 100 |
|
User Rollbacks (USER_ROLLBACKS) |
Number of rollbacks |
-- |
double |
No |
All |
V$SESSTAT.VALUE |
|
VA DeviceID (VADEVICEID) |
Device ID of virtual agent. |
-- |
string(256) |
No |
All |
Remote Monitor Collector |
|
Waiting Locks (WAITING_LOCKS) |
Number of locks owned by another session that this session is waiting for Correct values cannot be collected in this field, and 0 is always displayed. |
-- |
double |
No |
All |
-- |
|
Write % (WRITE_PERCENTAGE) |
Percentage ratio of write operations to all physical I/O operations |
-- |
double |
No |
All |
(physical writes / (physical reads + physical writes)) * 100 |