Current Sessions Stat Summary (PD_PDS3)
- Organization of this page
Function
The Current Sessions Stat Summary (PD_PDS3) record stores performance data indicating the status of all active sessions for an instance at a specific point in time.
Default and changeable values
Item |
Default value |
Changeable |
---|---|---|
Collection Interval |
600 |
Y |
Collection Offset |
110 |
Y |
Log |
No |
Y |
LOGIF |
(Blank) |
Y |
Over 10 Sec Collection Time |
No |
N |
ODBC key fields
None
Lifetime
From the creation to the deletion of an Oracle instance
Record size
-
Fixed part: 986 bytes
-
Variable part: 0 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 database manipulation language (DML) statements |
-- |
double |
No |
All |
db block changes / user commits |
Block Visits/Tran (BLOCK_VISITS_PER_TRANSACTION) |
Number of times a work database was loaded per transaction |
-- |
double |
No |
All |
(db block gets + consistent gets) / user commits |
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) |
Ratio (as a percent) of the number of queries that change data (insertion, update, and deletion) to the number of queries (search, insertion, update, deletion) executed on the database |
-- |
double |
No |
All |
(db block changes / (block gets + consistent gets)) * 100 |
Consistent Change % (CONSISTENT_CHANGE_PERCENTAGE) |
Ratio (as a percent) of the number of times rollback entries were applied to maintain read consistency to the number of read consistency requests by the application |
-- |
double |
No |
All |
(consistent changes / consistent gets) * 100 |
Continued Row % (CONTINUED_ROW_PERCENTAGE) |
Percentage of fetched rows that were longer than one block or were 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 DML enqueuing (locking) in active session |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Disk Sorts (SORTS_DISK) |
Number of disk sort operations |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Lock Conversions (LOCK_CONVERSIONS) |
Number of enqueues (locks) whose mode changed (such as from share to lock) |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Lock Releases (LOCK_RELEASES) |
Number of times enqueuing (locking) was released by active session (this statistic is the same as the number of lock requests) |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Lock Requests (LOCK_REQUESTS) |
Number of times enqueuing (locking) was requested by active session |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Lock Timeouts (LOCK_TIMEOUTS) |
Number of times enqueuing (locking) request was not permitted by the active session within the specified wait time |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Lock Waits (LOCK_WAITS) |
Number of times lock request was placed in wait status by active session (the number of lock requests that were not placed in wait status equals the number of lock requests minus the number of enqueued waits) |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Logical Reads (LOGICAL_READS) |
Sum of the number of logical read operations in read consistency mode and the number of requests to the current copy of the block |
-- |
double |
No |
All |
db block gets + consistent gets |
Non-Index Lookups % (NON_INDEX_LOOKUPS) |
Percentage of full table scans where no caching is performed |
-- |
double |
No |
All |
(table scans (long tables) / (table scans (short tables) + table scans (long tables))) * 100 |
Physical Reads (PHYSICAL_READS) |
Number of times database block was actually read from disk by active session |
-- |
double |
No |
All |
physical reads - physical reads direct - physical reads direct (lob) |
Physical Writes (PHYSICAL_WRITES) |
Number of physical write operations on disk by DBWR |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Record Time (RECORD_TIME) |
Collection termination time for the performance data stored in the record |
-- |
time_t |
No |
All |
Agent Collector |
Record Type (INPUT_RECORD_TYPE) |
Record name (always PDS3) |
-- |
string(4) |
No |
All |
Agent Collector |
Recursive Calls (RECURSIVE_CALLS) |
Number of user calls processed |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Recursive to User Call % (RECURSIVE_TO_USER_CALL_PERCENTAGE) |
Correct values cannot be collected for this field. Ratio (as a percent) of recursive calls to user calls |
-- |
double |
No |
All |
(recursive calls / user calls) * 100 |
Redo Log Space Requests (REDO_LOG_SPACE_REQUESTS) |
Number of times that, because the active log file was full, the Oracle server had to wait for disk space to be allocated for a REDO log entry. |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Redo Log Space Wait % (REDO_LOG_SPACE_WAIT_PERCENTAGE) |
Wait rate for allocations of the disk area to the REDO log entry |
-- |
double |
No |
All |
(redo log space requests / redo entries) * 100 |
Row Source % (ROW_SOURCE_PERCENTAGE) |
Percentage of all rows that were obtained by full table |
-- |
double |
No |
All |
(table scan rows gotten / (table fetch by rowid + table scan rows gotten)) * 100 |
SQL Net Bytes Rcvd (SQL_NET_BYTES_RECEIVED) |
Number of bytes the active sessions received from clients via SQL*Net |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
SQL Net Bytes Sent (SQL_NET_BYTES_SENT) |
Number of bytes the active sessions sent to clients via SQL*Net |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Session CPU Usage (SESSION_CPU_USAGE) |
Total CPU time in hundredths of a second used to execute statements during data collection |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Session Cursor Cache Count (SESSION_CURSOR_CACHE_COUNT) |
Number of session cursors cached (the maximum number of cursors that can be cached is determined by the SESSION_CACHED_CURSORS parameter in the init.ora file) |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Session Cursor Cache Hit % (SESSION_CURSOR_CACHE_HIT_PERCENTAGE) |
Percentage of session cursors that were reused |
-- |
double |
No |
All |
(session cursor cache hits / session cursor cache count) * 100 |
Session Cursor Cache Hits (SESSION_CURSOR_CACHE_HITS) |
Number of times cached session cursor was reused |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Session PGA Memory (SESSION_PGA_MEMORY) |
Size of PGA memory used by active session during data collection (in bytes) |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Session UGA Memory (SESSION_UGA_MEMORY) |
Size of UGA memory used by active session (in bytes) |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Sessions (SESSIONS) |
Number of sessions during data collection |
-- |
ulong |
No |
All |
COUNT(V$SESSION) |
Sort Overflow % (SORT_OVERFLOW_PERCENTAGE) |
Percentage of sorts that used 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 |
Agent Collector |
User Calls (USER_CALLS) |
Number of user calls processed by active sessions |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
User Calls / Parse (USER_CALLS_PER_PARSE) |
Percentage indicating how well the application is managing the context area |
-- |
double |
No |
All |
user calls / parse count (total) |
User Commits (USER_COMMITS) |
Number of transactions by active session |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
User Rollback % (USER_ROLLBACK_PERCENTAGE) |
Percentage of application transactions that failed (were rolledback) |
-- |
double |
No |
All |
(user rollbacks / (user commits + user rollbacks)) * 100 |
User Rollbacks (USER_ROLLBACKS) |
Number of rollbacks by active session |
-- |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Write % (WRITE_PERCENTAGE) |
Ratio (as a percent) of physical writes to all physical I/Os (reads and writes) |
-- |
double |
No |
All |
(physical writes / (physical reads + physical writes)) * 100 |