System Stat Summary Interval (PI)
- Organization of this page
Function
The System Stat Summary Interval (PI) record stores performance data, taken at specific intervals since the start of an instance, about key performance indicators.
Default and changeable values
Item |
Default value |
Changeable |
---|---|---|
Collection Interval |
60 |
Y |
Collection Offset |
0 |
Y |
Log |
Yes |
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: 1,974 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 DML operation #2 |
AVG |
double |
Yes#6 |
All |
db block changes / user commits |
Block Get/sec (BLOCK_GET_RATE) |
Rate at which the application referenced the database#2 |
AVG |
double |
Yes#6 |
All |
(db block gets + consistent gets) / second in interval |
Block Visits/Tran (BLOCK_VISITS_PER_TRANSACTION) |
Number of times a work database was loaded per transaction#2 |
AVG |
double |
Yes#6 |
All |
(db block gets + consistent gets) / user commits |
Buffer Busy Wait % (BUFFER_BUSY_WAIT_PERCENTAGE) |
Percentage ratio of buffer busy waits#2 |
AVG |
double |
Yes#6 |
All |
(V$SYSTEM_EVENT.TOTAL_WAITS where EVENT = 'buffer busy waits' / (consistent gets + db block gets)) * 100 |
Cache Hit % (CACHE_HIT_PERCENTAGE) |
Buffer cache usage#2 |
AVG |
double |
Yes#6 |
All |
(1 - (physical reads cache / (consistent gets from cache + db block gets from cache))) * 100 |
Call/sec (CALL_RATE) |
Work demand rate applied to the instance by all work resources#2 |
AVG |
double |
Yes#6 |
All |
recursive calls + user calls / seconds in interval |
Calls/Tran (CALLS_PER_TRANSACTION) |
Rate at which client requests were executed per transaction. You can use the value of this field to detect a change in the application or the utilization status. This value may increase significantly if unique queries increase.#2 |
AVG |
double |
No |
All |
user calls / user commits |
Changed Block % (CHANGED_BLOCK_PERCENTAGE) |
Percentage ratio of difference between query and database manipulation language (DML) in the database application. This value changes according to indexes and application utilization status.#2 |
AVG |
double |
Yes#6 |
All |
(db block changes / (block gets + consistent gets)) * 100 |
Consistent Change % (CONSISTENT_CHANGE_PERCENTAGE) |
Percentage indicating the extents for which the application needed to check the consistency of read operations#2 |
AVG |
double |
Yes#6 |
All |
(consistent changes / consistent gets) * 100 |
Continued Row % (CONTINUED_ROW_PERCENTAGE) |
Percentage ratio of continued rows. The value is close to 0 unless the application handles LONG columns. #2 |
AVG |
short |
Yes#6 |
All |
(table fetch continued row / (table fetch by rowid + table scan rows gotten)) * 100 |
Current Logons (CURRENT_LOGONS) |
Number of current logons to Oracle Database#2 |
AVG |
ulong |
No |
All |
V$SYSSTAT.VALUE |
Deadlocks (LOCK_DEADLOCKS) |
Number of deadlocks caused by locked DML processing#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Dict Cache Get Miss % (DICTIONARY_CACHE_GET_MISSES_PERCENTAGE) |
Percentage ratio of data requests issued due to cache miss#2 |
AVG |
double |
Yes#6 |
All |
(SUM(V$ROWCACHE.GETMISSES) / SUM(V$ROWCACHE.GETS)) * 100 |
Disk Sorts (SORTS_DISK) |
Number of disk sort operations#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Free List Wait Events (FREE_LIST_WAIT_EVENTS) |
Number of wait events in the free list#2 |
AVG |
double |
Yes |
All |
V$WAITSTAT.COUNT where class = 'free list' |
I/O Ops/sec (IO_RATE) |
Number of I/O operations per second#2 |
AVG |
double |
No |
All |
(physical reads + physical writes) / seconds in interval |
Lib Cache Miss % (LIBRARY_CACHE_MISS_PERCENTAGE) |
Library cache miss rate. This field means the ratio of times the allocated objects in library cache are reloaded. As the value of this field increases, the amount of resources in use also increases. #2 |
AVG |
double |
Yes#6 |
All |
(SUM(V$LIBRARYCACHE.RELOADS) SUM(V$LIBRARYCACHE.PINS)) * 100 |
Lock Conversions (LOCK_CONVERSIONS) |
Number of enqueues (locks) whose mode was changed (such as from share to lock)#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Lock Hit % (LOCK_HIT_PERCENTAGE) |
Percentage ratio of the number of accesses to data blocks to the total number of data block accesses. However, this is limited to cases that do not request a lock conversion. Only valid with an Oracle RAC configuration. #2 |
AVG |
double |
Yes#6 |
All |
((consistent gets - global enqueue gets async) / consistent gets) * 100 |
Lock Releases (LOCK_RELEASES) |
Number of times enqueuing (locking) was released#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Lock Requests (LOCK_REQUESTS) |
Number of times enqueuing (locking) was requested#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Lock Timeouts (LOCK_TIMEOUTS) |
Number of times an enqueuing (locking) request was not permitted within the allocated time#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Lock Waits (LOCK_WAITS) |
Number of times an enqueuing (locking) request was placed in wait status. The difference between the enqueuing requests count and the enqueuing waits count is the number of times the request was not treated as an enqueuing request. #2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Logical Reads (LOGICAL_READS) |
Number of logical read operations in read consistency mode and number of requests to the current copy of blocks#2 |
AVG |
double |
Yes |
All |
db block gets + consistent gets |
Memory Sorts (SORTS_MEMORY) |
Number of sort operations in memory#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Non-Index Lookups % (NON_INDEX_LOOKUPS) |
Percentage ratio of full table scans that do not involve caching#2 |
AVG |
double |
Yes#6 |
All |
(table scans (long tables) / (table scans (short tables) + table scans (long tables))) * 100 |
Physical Reads (PHYSICAL_READS) |
Number of physical read operations on database block from disk#2 |
AVG |
double |
Yes |
All |
physical reads - physical reads direct - physical reads direct (lob) |
Physical Writes (PHYSICAL_WRITES) |
Number of physical write operations on the disk by DBWR#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Ping Write % (PING_WRITE_PERCENTAGE) |
A large value means that lock conversion occurred frequently#2 |
AVG |
double |
Yes#6 |
All |
(DBWR cross instance writes / physical writes) * 100 |
Read/sec (READ_RATE) |
Number of read operations per second#2 |
AVG |
double |
No |
All |
physical reads / seconds in interval |
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 PI)#1 |
COPY |
string(4) |
No |
All |
Agent Collector |
Recursive Calls (RECURSIVE_CALLS) |
Number of user calls processed#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Recursive To User Call % (RECURSIVE_TO_USER_CALL_PERCENTAGE) |
Correct values cannot be collected in this field. Percentage indicating overhead#2 |
AVG |
double |
Yes#6 |
All |
(recursive calls / user calls) * 100 |
Redo Alloc Immediate % (REDO_ALLOC_IMMEDIATE_HIT_PERCENTAGE) |
Success rate of immediately acquiring REDO allocation latch#2 |
AVG |
double |
Yes#6 |
All |
(1 - (V$LATCH.IMMEDIATE_MISSES / (V$LATCH.IMMEDIATE_GETS + V$LATCH.IMMEDIATE_MISSES))) * 100 where V$LATCH.NAME = 'redo allocation' |
Redo Alloc Willing to Wait % (REDO_ALLOC_WILLING_TO_WAIT_HIT_PERCENTAGE) |
Success rate of acquiring REDO allocation latch from cache#2 |
AVG |
double |
Yes#6 |
All |
(1 - (V$LATCH.MISSES / V$LATCH.GETS)) * 100 where name = 'redo allocation' |
Redo Copy Immediate % (REDO_COPY_IMMEDIATE_HIT_PERCENTAGE) |
Success rate of immediately acquiring REDO copy latch#2 |
AVG |
double |
Yes#6 |
All |
(1 - (V$LATCH.IMMEDIATE_ MISSES / (V$LATCH.IMMEDIATE_GETS + V$LATCH.IMMEDIATE_MISSES))) * 100 where V$LATCH.NAME = 'redo copy' |
Redo Copy Willing to Wait % (REDO_COPY_WILLING_TO_WAIT_HIT_PERCENTAGE) |
Success rate of acquiring REDO copy latch from cache#2 |
AVG |
double |
Yes#6 |
All |
(1 - (V$LATCH.MISSES / V$LATCH.GETS)) * 100 where name = 'redo copy' |
Redo Log Buffer Alloc Retries (REDO_LOG_BUFFER_ALLOC_RETRIES) |
Number of waits that occurred when an attempt was made to allocate the REDO log buffer |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Redo Log Buffer Wait % (REDO_LOG_BUFFER_WAIT_PERCENTAGE) |
Percentage of waits that occurred when an attempt was made to allocate the REDO log buffer |
AVG |
double |
Yes#6 |
All |
(redo buffer allocation retries / redo entries) * 100 |
Redo Log Space Requests (REDO_LOG_SPACE_REQUESTS) |
Number of times Oracle must wait for disk spaces to be allocated to REDO log entry because the active log file is full. #2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Redo Log Space Wait % (REDO_LOG_SPACE_WAIT_PERCENTAGE) |
Percentage of waiting time until disk space is allocated for the REDO log entry#2 |
AVG |
double |
Yes#6 |
All |
(redo log space requests / redo entries) * 100 |
Row Source % (ROW_SOURCE_PERCENTAGE) |
Percentage ratio of rows obtained by full-table scan#2 |
AVG |
double |
Yes#6 |
All |
(table scan rows gotten / (table fetch by rowid + table scan rows gotten)) * 100 |
SQL Executing (SQL_EXECUTING) |
This field is not supported. Number of current SQL executions |
AVG |
double |
No |
Not supported |
Agent Collector |
SQL Net Bytes Rcvd (SQL_NET_BYTES_RECEIVED) |
Amount of data received from clients via SQL*Net#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
SQL Net Bytes Sent (SQL_NET_BYTES_SENT) |
Amount of data sent to clients via SQL*Net#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Session CPU Usage (SESSION_CPU_USAGE) |
If the value of the TIMED_STATISTICS parameter in the init.ora file is TRUE, the CPU time used (in 1/100 seconds); if the parameter value is FALSE, this field contains 0.#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Session Cursor Cache Count (SESSION_CURSOR_CACHE_COUNT) |
Number of analysis calls for the session's cursor calls#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Session Cursor Cache Hit % (SESSION_CURSOR_CACHE_HIT_PERCENTAGE) |
Hit rate of analysis calls in session's cursor cache#2 |
AVG |
double |
No |
All |
(session cursor cache hits / session cursor cache count) * 100 |
Session Cursor Cache Hits (SESSION_CURSOR_CACHE_HITS) |
Number of times a cursor was found in the session's cursor cache by analysis call#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Session PGA Memory (SESSION_PGA_MEMORY) |
Size of PGA memory currently being used in bytes#2 |
AVG |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Session UGA Memory (SESSION_UGA_MEMORY) |
Size of used session memory in bytes#2 |
AVG |
double |
No |
All |
SUM(V$SESSTAT.VALUE) |
Sort Overflow % (SORT_OVERFLOW_PERCENTAGE) |
Percentage ratio of sort operations using a temporary segment #2 |
AVG |
double |
Yes#6 |
All |
(sorts (disk) / (sorts (memory) + sorts (disk))) * 100 |
Start Time (START_TIME) |
Collection start time for the performance data stored in the record#1 |
COPY |
time_t |
No |
All |
Agent Collector |
Sys Undo Blk Wait Events (SYSTEM_UNDO_BLOCK_WAIT_EVENTS) |
Number of block wait events for the system's rollback segment #2 |
AVG |
double |
Yes |
All |
V$WAITSTAT.COUNT where class = 'system undo block' |
Sys Undo Hdr Wait Events (SYSTEM_UNDO_HEADER_WAIT_EVENTS) |
Number of header block wait events for the system's rollback segment #2 |
AVG |
double |
Yes |
All |
V$WAITSTAT.COUNT where class = 'system undo header' |
Total Logons (TOTAL_LOGONS) |
Number of logins to the server #2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Total SQL Executions (TOTAL_SQL_EXECUTIONS) |
Total number of SQL executions #2 |
AVG |
double |
Yes |
All |
execute count |
Trans/sec (TRANSACTION_RATE) |
Number of transactions per second#2 |
AVG |
double |
No |
All |
user commits / seconds in interval |
Undo Blk Wait Events (UNDO_BLOCK_WAIT_EVENTS) |
Number of block wait events for other rollback segments#2 |
AVG |
double |
Yes |
All |
V$WAITSTAT.COUNT where class = 'undo block' |
Undo Hdr Wait Events (UNDO_HEADER_WAIT_EVENTS) |
Number of header block wait events for other rollback segments#2 |
AVG |
double |
Yes |
All |
V$WAITSTAT.COUNT where class = 'undo header' |
User Calls (USER_CALLS) |
Number of user calls processed#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
User Calls / Parse (USER_CALLS_PER_PARSE) |
Application management status in the context area #2 |
AVG |
double |
Yes#6 |
All |
user calls / parse count (total) |
User Commits (USER_COMMITS) |
Number of transactions#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
User Rollback % (USER_ROLLBACK_PERCENTAGE) |
Failure rate of application transactions #2 |
AVG |
double |
No |
All |
(user rollbacks / (user commits + user rollbacks)) * 100 |
User Rollbacks (USER_ROLLBACKS) |
Number of rollbacks#2 |
AVG |
double |
Yes |
All |
V$SYSSTAT.VALUE |
Write % (WRITE_PERCENTAGE) |
Percentage ratio of write operations #2 |
AVG |
double |
No |
All |
(physical writes / (physical reads + physical writes)) * 100 |
Writes/sec (WRITES_RATE) |
Number of write operations per second#2 |
AVG |
double |
No |
All |
physical writes / seconds in interval |
- #6
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The field value is calculated based on the delta of the amount of collected data from Oracle Database.