Cache Summary (PD_PDCS)
- Organization of this page
Function
The Cache Summary (PD_PDCS) record stores performance data indicating the status of each cache in the system global area (SGA) at a specific point in time.
Default and changeable values
Item |
Default Value |
Changeable |
---|---|---|
Collection Interval |
300 |
Y |
Collection Offset |
40 |
Y |
Log |
No |
Y |
LOGIF |
(Blank) |
Y |
Over 10 Sec Collection Time |
Yes |
N |
ODBC Key Fields
None
Lifetime
From the creation to the deletion of an Oracle instance
Record Size
-
Fixed part: 886 bytes
-
Variable part: 0 bytes
Fields
PFM - View name (PFM - Manager name) |
Description |
Summary |
Format |
Delta |
Supported Version |
Data Source |
---|---|---|---|---|---|---|
Cursor Open Hit % (CURSOR_OPEN_HIT_PERCENTAGE) |
Percentage of cursors found in cursor searches that were open cursors |
-- |
double |
No |
All |
V$SYSTEM_CURSOR_CACHE.HIT_RATIO * 100 |
Cursor Open Hits (CURSOR_OPEN_HITS) |
Total cursor open hits |
-- |
double |
No |
All |
V$SYSTEM_CURSOR_CACHE.HITS |
Cursor Opens (CURSOR_OPENS) |
Total cursor opens |
-- |
double |
No |
All |
V$SYSTEM_CURSOR_CACHE.OPENS |
Database Object Cache Keeps (DATABASE_OBJECT_CACHE_KEEPS) |
Number of objects kept |
-- |
ulong |
No |
All |
COUNT(V$DB_OBJECT_CACHE) where KEPT='YES' |
Database Object Cache Locks (DATABASE_OBJECT_CACHE_LOCKS) |
Number of users locking objects in cache |
-- |
long |
No |
All |
SUM(V$DB_OBJECT_CACHE.LOCKS) |
Database Object Cache Pins (DATABASE_OBJECT_CACHE_PINS) |
Number of users who have acquired objects in cache |
-- |
long |
No |
All |
SUM(V$DB_OBJECT_CACHE.PINS) |
Dict Cache Fixed (DICTIONARY_CACHE_FIXED) |
Number of entries fixed in cache |
-- |
double |
No |
All |
SUM(V$ROWCACHE.FIXED) |
Dict Cache Flushes (DICTIONARY_CACHE_FLUSHES) |
Number of disk flushes |
-- |
double |
No |
All |
SUM(V$ROWCACHE.FLUSHES) |
Dict Cache Get Miss % (DICTIONARY_CACHE_GET_MISSES_PERCENTAGE) |
Percentage of data requests for which a cache miss occurred |
-- |
double |
No |
All |
(SUM(V$ROWCACHE.GETMISSES) / SUM(V$ROWCACHE.GETS)) * 100 |
Dict Cache Get Misses (DICTIONARY_CACHE_GET_MISSES) |
Number of data requests for which a cache miss occurred |
-- |
double |
No |
All |
SUM(V$ROWCACHE.GETMISSES) |
Dict Cache Gets (DICTIONARY_CACHE_GETS) |
Number of requests for information about data objects |
-- |
double |
No |
All |
SUM(V$ROWCACHE.GETS) |
Dict Cache Modifications (DICTIONARY_CACHE_MODIFICATIONS) |
Number of insert, update, and delete operations |
-- |
double |
No |
All |
SUM(V$ROWCACHE.MODIFICATIONS) |
Dict Cache Scan Completes (DICTIONARY_CACHE_SCAN_COMPLETES) |
Number of times scanning of a list of dependent entries was completed |
-- |
double |
No |
All |
SUM(V$ROWCACHE.SCANCOMPLETES) |
Dict Cache Scan Misses (DICTIONARY_CACHE_SCAN_MISSES) |
Number of times data was not found in cache by scanning |
-- |
double |
No |
All |
SUM(V$ROWCACHE.SCANMISSES) |
Dict Cache Scan Misses % (DICTIONARY_CACHE_SCAN_MISSES_PERCENTAGE) |
Percentage of times data was not found in cache by scanning |
-- |
double |
No |
All |
(SUM(V$ROWCACHE.SCANMISSES) / SUM(V$ROWCACHE.SCANS)) * 100 |
Dict Cache Scans (DICTIONARY_CACHE_SCANS) |
Number of scan requests |
-- |
double |
No |
All |
SUM(V$ROWCACHE.SCANS) |
Dict Cache Usage (DICTIONARY_CACHE_USAGE) |
Number of cache entries with valid data |
-- |
ulong |
No |
All |
SUM(V$ROWCACHE.USAGE) |
Lib Cache Get Hit % (LIBRARY_CACHE_GET_HIT_PERCENTAGE) |
Percentage of times objects were found in library cache |
-- |
double |
No |
All |
(SUM(V$LIBRARYCACHE.GETHITS) / SUM(V$LIBRARYCACHE.GETS)) * 100 |
Lib Cache Get Hits (LIBRARY_CACHE_GET_HITS) |
Number of times objects were found in library cache |
-- |
double |
No |
All |
SUM(V$LIBRARYCACHE.GETHITS) |
Lib Cache Gets (LIBRARY_CACHE_GETS) |
Number of locks requested for objects in library cache |
-- |
double |
No |
All |
SUM(V$LIBRARYCACHE.GETS) |
Lib Cache Invalidations (LIBRARY_CACHE_INVALIDATIONS) |
Number of times a nonpermane nt library object (such as a shared SQL area) was invalid |
-- |
double |
No |
All |
SUM(V$LIBRARYCACHE.INVALIDATIONS) |
Lib Cache Miss % (LIBRARY_CACHE_MISS_PERCENTAGE) |
Library cache miss percentage: The percentage of objects in the library cache that had to be reloaded into the library cache. A higher percentage indicates greater resource usage. |
-- |
double |
No |
All |
(SUM(V$LIBRARYCACHE.RELOADS) / SUM(V$LIBRARYCACHE.PINS)) * 100 |
Lib Cache Pin Hit % (LIBRARY_CACHE_PIN_HIT_PERCENTAGE) |
Ratio (as a percent) of the LIBRARY_CACHE_PIN_HITS value to the LIBRARY_CACHE_PINS value |
-- |
double |
No |
All |
(SUM(V$LIBRARYCACHE.PINHITS) / SUM(V$LIBRARYCACHE.PINS)) * 100 |
Lib Cache Pin Hits (LIBRARY_CACHE_PIN_HITS) |
Number of times an object acquired or accessed by the system had already been placed in cache and initialized |
-- |
double |
No |
All |
SUM(V$LIBRARYCACHE.PINHITS) |
Lib Cache Pins (LIBRARY_CACHE_PINS) |
Number of times the system acquired an object in cache to access it |
-- |
double |
No |
All |
SUM(V$LIBRARYCACHE.PINS) |
Lib Cache Reloads (LIBRARY_CACHE_RELOADS) |
Number of times the system needed to reinitialize a library object and load it along with the data because it had not been used recently or it was invalid |
-- |
double |
No |
All |
SUM(V$LIBRARYCACHE.RELOADS) |
Record Time (RECORD_TIME) |
Collection termination time for the performance data stored in the record |
-- |
time_t |
No |
All |
Agent Collector |
Record Type (INPUT_RECORD_TYPE) |
Record name (always PDCS) |
-- |
string(4) |
No |
All |
Agent Collector |
SQL Executing (SQL_EXECUTING) |
Total number of users currently executing SQL statements |
-- |
double |
No |
All |
SUM(V$SQLAREA.USERS_EXECUTING) |
Start Time (START_TIME) |
Collection start time for the performance data stored in the record |
-- |
time_t |
No |
All |
Agent Collector |
Total SQL Executions (TOTAL_SQL_EXECUTIONS) |
Total number of SQL executions |
-- |
double |
No |
All |
execute count |