Release 9.2.0
Part Number A96672-01
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| Oracle SNMP Support Reference Guide Release 9.2.0 Part Number A96672-01 |
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This appendix provides information to help you interpret individual variables in the private Oracle Database MIB. Specifically, it includes sections covering SNMP variables in the following tables:
For information about the database instance performance ratios listed in this appendix, see the section Most Useful Database Instance Performance Ratios in Chapter 4, "Designing Management Applications Based on Oracle MIBs". For more information about the Oracle database server and specific topics covered in this appendix, see the Oracle9i Database Reference, the Oracle9i Application Developer's Guide - Fundamentals, and the Oracle9i Database Concepts specific to your system.
The oraDbSysTable contains various measurements used to support database activities of current sessions on the managed node. This information has been found to be particularly useful for monitoring global database instance performance.
Each entry in the oraDbSysTable represents a current database instance on the node. Each entry is indexed by rdbmsDb Index. However, because rdbmsDbTable contains an entry for each database configured for SNMP support, whether or not it is actively open, there may or may not be a one-to-one correspondence between entries in the two tables at any point in time. (For details about this index, see Appendix D, "Interpreting Variables of the Public RDBMS MIB.") The value of each oraDbSysTable variable is retrieved directly from a corresponding field in the V$SYSSTAT table for that database instance on the managed node.
In many cases, a variable is meaningful only when considered in conjunction with other variables, often as a ratio. For more information on the ratios mentioned in the following variable descriptions, and for their significance in tuning the Oracle database server, see the Oracle9i Database Performance Guide and Reference specific to your system.
Table A-1 lists each variable of the oraDbSysTable and its corresponding object ID.
A description of each of these variables follows.
Counter32
read-only
This variable is retrieved directly from the value for CONSISTENT CHANGES in V$SYSSTAT. It is incremented each time that a consistent get operation cannot accept the block in its current state, owing to a change made since the query consistency point.
oraDbSysConsistentChanges is used to calculate the following database instance performance ratio: the consistent change ratio.
two or more orders of magnitude less than the value of oraDbSysConsistentGets
important
oraDbSysConsistentGets
counter
Counter32
read-only
This variable is retrieved directly from the value for CONSISTENT GETS in V$SYSSTAT. This value is incremented each time that the Oracle Buffer Manager is requested to locate a database block as part of a read consistent operation (a query). Only if the requested block is not found in Oracle's Buffer Cache will consistent get result in physical I/O.
oraDbSysConsistentGets is used to calculate the following database instance performance ratios: block get rate, block visits per transaction, cache hit ratio, changed block ratio, and the consistent change ratio.
0 - 4294967295; can increment at several thousand per second in the largest systems, so this variable is definitely a "wraparound" candidate
very important
oraDbSysUserCommits, oraDbSysConsistentChanges, oraDbSysPhysReads, oraDbSysDbBlockChanges, oraDbSysDbBlockGets
counter
Counter32
read-only
This variable is retrieved directly from the value for DB BLOCK CHANGES in V$SYSSTAT. It is incremented each time that a database block is in memory to create a "dirty block." This statistic is a rough indication of total database work.
oraDbSysDbBlockChanges is used to calculate the following database instance performance ratios: block changes per transaction, and the changed block ratio.
0 - 4294967295; can increment at several thousand per second in the largest systems, so this variable is definitely a "wraparound" candidate; value tends to be lower than that for oraDbSysConsistentGets
one of the lesser measures of work rate or throughput
oraDbSysBlockGets, oraDbSysConsistentGets, oraDbSysUserCalls
counter
Counter32
read-only
This variable is retrieved directly from the value for DB BLOCK GETS in V$SYSSTAT. It is incremented each time the buffer manager is asked for a database block in current mode, that is, regardless of read consistency. This mode is used to locate blocks which are to be updated, and also to access control information such as segment headers. Only if the requested block is not found in Oracle's Buffer cache will a db block get result in physical I/O.
oraDbSysBlockGets is used to calculate the following database instance performance ratios: block get rate, block visits per transaction, the cache hit ratio, and the changed block ratio.
0 - 4294967295; can increment at several thousand per second in the largest systems, so this variable is definitely a "wraparound" candidate.
very important
oraDbSysDbBlockChanges, oraDbSysConsistentGets, oraDbSysPhysReads, oraDbSysUserCalls
counter
Counter32
read-only
The "free buffer inspected" parameter from V$SYSTAT.
0 - 4294967295
This indicates the number of reusable buffers skipped over from the end of the Least Recently Used (LRU) queue in order to find a buffer. The difference between this and "dirty buffers inspected" equals the number of buffers that could not be used beause they were busy or needed to be written after rapid aging out. They may have a user, a waiter, or be being read or written.
oraDbSysFreeBufferRequested
counter
Counter32
read-only
The "free buffer requested" parameter from V$SYSTAT.
0 - 4294967295
This is the count of the number of times a free buffer was requested to create or load a block.
oraDbSysFreeBufferInspected
counter
Counter32
read-only
This variable is retrieved directly from the value for PARSE COUNT(total) in V$SYSSTAT. It counts the number of parse calls received by the RDBMS from both connected applications and recursive calls. In Oracle, parse calls are frequently satisfied by reference to the Shared SQL area and this statistic does not measure the number of parses which have taken place, only the number of calls.
oraDbSysParseCount is used to calculate the following database instance performance ratio: user calls per parse.
0 - 4294967295; unlikely to increment at a rate greater than a few hundred per second
important
oraDbLibraryCacheTable variables, oraDbSysUserCalls
counter
Counter32
read-only
This variable is retrieved directly from the value for PHYSICAL READS in V$SYSSTAT. It increments each time a DB Block is retrieved from the disk subsystem, but is not necessarily equal to the number of I/O requests made to the host operating system, as multiblock I/O may be used. A physical read can be viewed as an SGA Buffer Cache miss, hampering throughput (contention induction) and CPU (code pathlength) processing.
oraDbSysPhysReads is used to calculate the following database instance performance ratio: the cache hit ratio.
0 - 4294967295; unlikely to increment at a rate greater than a few hundred per second
very important
oraDbSysConsistentGets, oraDbSysDbBlockGets
counter
Counter32
read-only
This variable is retrieved directly from the value for PHYSICAL WRITES in V$SYSSTAT. It increments each time a DB Block is written to disk. All writes are performed either by DBWR or LGWR, two background processes responsible for getting Blocks out of the SGA and back on disk.
0 - 4294967295; can increment at several thousand per second in the largest systems, so this variable is definitely a "wraparound" candidate
important
oraDbSysRedo family
counter
Counter32
read-only
This variable is retrieved directly from the value for REDO ENTRIES in V$SYSSTAT. Each time that REDO data is copied into the log buffer, this counter is incremented. The value varies in relation to how many changes are being made.
oraDbSysRedoEntries is used to calculate the following database instance performance ratio: redo log space wait ratio.
0 - 4294967295; can increment at several thousand per second in the largest systems, so this variable is definitely a "wraparound" candidate.
important
oraDbSysRedoLogSpaceRequests, oraDbSysRedoSyncWrites, oraDbSysUserCommits
counter
Counter32
read-only
This variable is retrieved directly from the value for REDO LOG SPACE REQUESTS in V$SYSSTAT. This counts the number of times that a server process had to wait to acquire an entry in the redo log.
oraDbSysRedoLogSpaceRequests is used to calculate the following database instance performance ratios: redo log space wait ratio.
0 - 10,000,000 (a value of 0 is ideal, but an increment of 1 or 2 per second might be acceptable)
important
oraDbSysRedoEntries
counter
Counter32
read-only
This variable is retrieved directly from the value for REDO SYNC WRITES parameter in V$SYSSTAT. It increments when a process waits for a ReDo write to complete, typically as a result of a Commit.
0 - 10,000,000 (typically increments at less than 1 per second)
less important
oraDbSysRedoEntries, oraDbSysRedoLogSpaceRequest, oraDbSysUserCommits
counter
Counter32
read-only
This variable is retrieved directly from the value for SORTS DISKS in V$SYSSTAT. It increments for each sort which has to allocate disk work space.
oraDbSysSortsDisks is used to calculate the following database instance performance ratio: the sort overflow ratio.
for OLTP it should be 0
important
oraDbSysRedoEntries, oraDbSysRedoLogSpaceRequest, oraDbSyncWrites, oraDbSysSortsMemory, oraDbUserCommits
counter
Counter32
read-only
This variable is retrieved directly from the value for SORTS MEMORY in V$SYSSTAT. It is incremented for each sort which does not require the allocation of work space on disk.
oraDbSysSortsMemory is used to calculate the following database instance performance ratio: the sort overflow ratio.
0 - 4294967295; unlikely to increment faster than tens per second, except in the largest systems
important
oraDbSysRedoEntries, oraDbSysRedoLogSpaceRequest, oraDbSyncWrites, oraDbSysSortsDisks, oraDbUserCommits
counter
Counter32
read-only
This variable is retrieved directly from the value for SORTS ROWS in V$SYSSTAT. It is incremented for each sort, regardless of whether the allocation of disk space was required.
0 - 4294967295
important
oraDbSysRedoEntries, oraDbSysRedoLogSpaceRequest, oraDbSyncWrites, oraDbSysSortsMemory, oraDbSortsDisks, oraDbUserCommits
counter
Counter32
read-only
This variable is retrieved directly from the value for TABLE FETCH BY ROWID in V$SYSSTAT. This counter increments when a row is fetched using a RowID (usually recovered from an index). It should be noted that this statistic records all rows visited by the database engine, whether or not they were return to the application.
oraDbSysTableFetchRowid is used to calculate the following database instance performance ratios: the continued row ratio and the row source ratio.
0 - 4294967295; can increment at several tens of thousands per second in the largest systems, so this variable is definitely a "wraparound" candidate
important
oraDbSysRedoEntries, oraDbSysRedoLogSpaceRequest, oraDbSyncWrites, oraDbSysSortsDisks, oraDbSysTableFetchContinuedRow, oraDbSysTableScanRows, oraDbUserCommits
counter
Counter32
read-only
This variable is retrieved directly from the value for TABLE FETCH CONTINUED ROW in V$SYSSTAT. It may be incremented either because a row has been encountered which spans more than a DB block, or because a migrated row has been retrieved by rowid.
oraDbSysTableFetchContinuedRow is used to calculate the following database instance performance ratio: the continued row ratio.
close to 0 unless long LONG values are in use.
important
oraDbSysTable FetchRowid, oraDbSysTableScanRows
counter
Counter32
read-only
This variable is retrieved directly from the value for TABLE SCAN BLOCKS GOTTEN in V$SYSSTAT. During scanning operations, the RDBMS retrieves each row sequentially. This counter increments each time the RDBMS steps into a new DB Block during the scan. oraDbSysTableScanBlocks indicates how many DB Blocks were Consistently Read from the Buffer Cache for the purpose of scanning. Comparing this to the value of oraDbSysConsistentGets suggests how much Consistent Read activity can be attributed to scanning.
0 - 3 billion; in OLTP very low; in DSS applications, a few thousand per second, so this variable is definitely a "wraparound" candidate.
important
oraDbSysConsistentGets
counter
Counter32
read-only
This variable is retrieved directly from the value for TABLE SCAN ROWS GOTTEN in V$SYSSTAT. This counter increases each time a row is processed during a Scan operation. Note that the row need not be parsed back to the calling application in order for it to be counted here.
oraDbSysTableScanRows is used to calculate the following database instance performance ratio: the row source ratio, and the continued row ratio.
0 - 100,000,000 per day
important
oraDbSysTableFetchContinuedRow, oraDbSysTableFetchRowid
counter
Counter32
read-only
This variable is retrieved directly from the value for TABLE SCANS LONG TABLES in V$SYSSTAT. Long tables are those whose number of data blocks below the high water mark exceeds the value of the initialization parameter SMALL _TABLE_THRESHOLD. DB Blocks visited in Long Full Table Scans are not prompted in the LRS List.
in OLTP, typically 0
important
oraDbSysTableScansShort
counter
Counter32
read-only
This variable is retrieved directly from the value for TABLE SCANS SHORT TABLES in V$SYSSTAT. Short tables can be defined as tables that do not meet the long table criteria, as defined by oraDbSysTableScansLong. Short tables are those whose number of data blocks above the low water mark is low than the value of the initialization parameter LONG_TABLE_THRESHOLD.
0 - 4294967295; can increment at a few hundred per second
important
oraDbSysTableScansLong
counter
Counter32
read-only
This variable is retrieved directly from the value for USER CALLS in V$SYSSTAT. A user call is a Parse, an Execute, or a Fetch. With the Oracle server's deferred and bundled execution capabilities, this statistic will not necessarily correlate well with client/server message traffic.
oraDbSysUserCalls is used to calculate the following database instance performance ratios: block changes per transaction, the call rate, calls per transaction, the recursive-to-user call ratio, the user call rate, and user calls per parse.
0 - 10,000,000 per day
very important
oraDbSysDbBlockChanges, oraDbSysParseCount, oraDbSysUserCommits
counter
Counter32
read-only
This variable is retrieved directly from the value for USER COMMITS in V$SYSSTAT. It records the number of database transactions successfully completed and records the number of aborted database transactions.
oraDbSysUserCommits is used to calculate the following database instance performance ratios: block visits per transaction, calls per transaction, and the transaction rate.
In most real world applications, the value is less the 1 per second.
In OLTP, very important
oraDbBlockGets, oraDbSysConsistentGets, oraDbUserCalls
counter
Counter32
read-only
This variable is retrieved directly from the value for USER ROLLBACKS in V$SYSSTAT. It records the number of aborted database transactions.
oraDbSysUserRollbacks is used to calculate the following database instance performance ratio: the user rollback ratio.
0 - 4294967295
important
oraDbSysUserCommits
counter
The oraDbTablespaceTable contains information on tablespaces within a current Oracle database instance. A tablespace is a logical portion of an Oracle database used to allocate storage for table and index data. In a production environment, tables can fill up as transaction activity mounts. Monitoring tablespace activity is important to avoid exhausting the tablespaces and causing spaces.
Each entry in the oraDbTablespaceTable represents a given tablespace within a current database instance. Each entry is indexed first by rdbmsDbIndex, and then oraDbTablespaceIndex; thus, there will normally be a one-to-many relationship between an rdbmsDbTable entry and corresponding oraDbTablespaceTable entries. (For details about rdbmsDbIndex, see Appendix D, "Interpreting Variables of the Public RDBMS MIB". The current value of each oraDbTablespaceTable variable is retrieved directly from a join of DBA_TABLESPACES, DBA_DATA_FILES, and DBA_FREE_SPACE selecting for the tablespace in question.
Table A-2 lists each of these variables and its corresponding object.
| Variable Name | Object ID |
|---|---|
| oraDbTablespaceIndex | 1.3.6.1.4.1.111.4.1.2.1.1 |
| oraDbTablespaceName | 1.3.6.1.4.1.111.4.1.2.1.2 |
| oraDbTablespaceSizeAllocated | 1.3.6.1.4.1.111.4.1.2.1.3 |
| oraDbTablespaceSizeUsed | 1.3.6.1.4.1.111.4.1.2.1.4 |
| oraDbTablespaceState | 1.3.6.1.4.1.111.4.1.2.1.5 |
| oraDbTablespaceLargestAvailableChunk | 1.3.6.1.4.1.111.4.1.2.1.6 |
INTEGER (1..2147483647)
not-accessible
A numeric index, unique among tablespaces within a single Oracle database instance. This index is assigned to these tablespaces based on the alphabetical order of their names. On most platforms, a hard file limit of 1023 database files exists, so this number is the practical upper limit. Although some administrators prefer a one-to-one relationship between tablespaces and database files, multiple files can comprise a tablespace.
1 - 1,000
very important
oraDbTablespaceName, rdbmsDbIndex
not applicable
DisplayString
read-only
Indicates the name of this tablespace, as retrieved from the value for TABLESPACE-NAME in DBA_TABLESPACES.
0 - 30 characters
important
oraDbTablespaceIndex
simple string
Integer32
read-only
Indicates the amount of disk space (in kilobytes) allocated for this tablespace. This is the sum of the sizes of the data files associated with the tablespace.
0 - 10 gigabytes
important
oraDbTablespaceSizeUsed
simple string
Integer32
read-only
Indicates the amount of disk space (in kilobytes) which is actually in use for storing data. This is the difference between the sum of the size of the datafiles associated with the tablespace and the sum of the size of the free spaces associated with the tablespace.
0 - value of oraDbTablespaceSizeAllocated
Significance
Very important
oraDbTablespaceSizeAllocated
gauge
INTEGER (1) online (2) offline, or (3) invalid
read-only
Indicates the current accessibility of this tablespace, as retrieved from the value for STATUS in DBA_TABLESPACES. If a tablespace is offline (2), then SQL statements cannot reference objects contained in the tablespace. An invalid (3) tablespace is one that has been dropped.
enumerated 1 - 3
very important
none
simple string or icon
Integer32
read-only
Indicates the size (in kilobytes) of the largest contiguous set of free data blocks in the tablespace. This variable is retrieved directly from the value for NEXT_EXTENT in DBA_TABLES. If there is any object in the tablespace whose NEXT_EXTENT value is greater than the layout chunk, that object will be unable to expand. This might cause a major problem, or it might not matter.
Less than or equal to (oraDbTablespaceSizeAllocated minus oraDbTablespaceSizeUsed)
important
oraDbTablespaceSizeAllocated, oraDbTablespaceSizeUsed
gauge
oraDbDataFileTable contains information on the data files within a current database instance on the managed node. A data file denotes an area of disk allocated for database data. Monitoring data files is important for two reasons; first, to determine whether space in files is being exhausted, and second to determine O/S response time in accessing data on disk, especially on platforms where there is no other way to measure disk queue length.
Each entry in the oraDbDataFileTable represents a given data file within a current database instance on the node. Each entry is indexed first by rdbmsDbIndex, and then by oraDbDataFileIndex; thus, there will normally be a one-to-many relationship between an rdbmsDbTable entry and corresponding oraDbDataFileTable entries. (For details about rdbmsDbIndex, see Appendix D, "Interpreting Variables of the Public RDBMS MIB") The current value of each oraDbDataFileTable variable is retrieved directly from a corresponding field in either V$FILESTAT or DBA_DATA_FILES for that data file within that database instance.
Table A-3 lists each variable of the oraDbDataFileTable and its corresponding object ID
| Variable Name | Object ID |
|---|---|
| oraDbDataFileIndex | 1.3.6.1.4.1.111.4.1.3.1.1 |
| oraDbDataFileName | 1.3.6.1.4.1.111.4.1.3.1.2 |
| oraDbDataFileSizeAllocated | 1.3.6.1.4.1.111.4.1.3.1.3 |
| oraDbDataFileDiskReads | 1.3.6.1.4.1.111.4.1.3.1.4 |
| oraDbDataFileDiskWrites | 1.3.6.1.4.1.111.4.1.3.1.5 |
| oraDbDataFileDiskReadBlocks | 1.3.6.1.4.1.111.4.1.3.1.6 |
| oraDbDataFileDiskWrittenBlocks | 1.3.6.1.4.1.111.4.1.3.1.7 |
| oraDbDataFileDiskReadTimeTicks | 1.3.6.1.4.1.111.4.1.3.1.8 |
| oraDbDataFileDiskWriteTimeTicks | 1.3.6.1.4.1.111.4.1.3.1.9 |
INTEGER(1..2147483647)
not-accessible
A numeric index, unique among data files associated with a single tablespace. The value of oraDbDataFileIndex is retrieved directly from the value of FILE_ID in DBA_DATA_FILES. For a small database, a tablespace typically contains 1 data file; for a large database (80 Gbytes), a tablespace typically contains 200 datafiles in a tablespace. The upper limit is hard coded as 1023.
1 - 400
very important
rdbmsDbIndex
not applicable
DisplayString
read-only
Indicates the fully-qualified name of this data file. The value is retrieved from the value of FILE_NAME in DBA_DATA_FILES.
10 - 100 characters; about 15 for raw partitions.
important
oraDbTablespaceName, because the file is a member of a tablespace.
simple string
Integer32
read-only
Indicates the allocated size (in kilobytes) of this data file, as retrieved from the value of BYTES in DBA_DATA_FILES. Indicates how much space has been used so far. Monitoring this variable is very important, because running out of space can require taking the database down, depending on which table this file supports. Normally, however, adding another data file to the Tablespace solves the problem.
100 Mbytes - 2 Gbytes
very important
none
simple string
Counter32
read-only
Indicates the total number of reads issued against this data file since database instance startup, as retrieved from the value of PHYRDS in V$FILESTAT.
10,000 - 100,000 or much more, depending on the life of the instance
less important
oraDbDataFileDiskReadBlocks, oraDbDataFileDiskReadTimeTicks
counter
Counter32
read-only
Indicates the total number of writes issued against this data file since database instance startup, as retrieved from the value of PHYWRTS in V$FILESTAT.
10,000 - 100,000 or much more, depending on the life of the instance
less important
oraDbDataFileDiskWriteBlocks, oraDbDataFileDiskWriteTimeTicks
counter
Counter32
read-only
Indicates the total number of physical blocks read from this data file since database instance startup. The value is retrieved from the value of PHYBLKRD in V$FILESTAT. The number of bytes read can be determined by multiplying this value by the value of oraDbConfigDbBlockSize, typically 2Kbytes.
10,000 - 100,000 or much more, depending on the life of the instance
important
oraDbConfigDbBlockSize, oraDbDataFileDiskReads
counter
Counter32
read-only
Indicates the total number of physical blocks written to this data file since database instance startup. The value is retrieved from the value of PHYBLKWRT in V$FILESTAT. The number of bytes written can be determined by multiplying this value by the value of the INIT.ORA parameter, DB_BLOCK_SIZE, typically 2Kbytes.
10,000 - 100,000 or much more, depending on the life of the instance
important
oraDbDataFileDiskWrites
counter
Counter32
read-only
Indicates the time spent writing to this data file since database instance startup IF the INIT.ORA parameter TIMED_STATISTICS is TRUE. (The unit of measurement on a UNIX platform is time ticks of 10 ms.) If TIMED_STATISTICS is FALSE, then a value of 0 is returned. The value of oraDbDataFileDiskReadTimeTicks is retrieved from the value of READTIM in V$FILESTAT.
Because knowing how long it takes to perform I/O per block is the important statistic, knowing this aggregate measure is not very significant. If the average time to do reads is generally exceeding a couple of ticks, then an I/O sybsystem response time problem exists. Most high performance disk drives can easily locate any sector on the disk in 10 ms.
0 - 4294967295
less important
oraDbDataFileDiskReads
clock
Counter32
read-only
Indicates the time spent writing to this data file since database instance startup IF the INIT.ORA parameter TIMED_STATISTICS is TRUE. (The unit of measurement on a UNIX platform is time ticks of 10 ms.) If TIMED_STATISTICS is FALSE, then a value of 0 is returned. The value of oraDbDataFileDiskWriteTimeTicks is retrieved from the value of WRITETIM in V$FILESTAT.
Because knowing how long it takes to perform I/O per block is the important statistic, knowing this aggregate measure is not very significant. If the average time to do writes is generally exceeding three ticks on non-mirrored data, then an I/O subsystem response time problem exists. Most high performance disk drives can easily perform a write in 15 ms.
Can wrap around the upper limit of 2147483647 in about three days of continuous instance operation for a busy database
less important
oraDbDataFileDiskWrites
clock
The oraDbLibraryCacheTable contains variables measuring library cache activity since the most recent database instance startup. A library cache is a memory structure containing shared SQL and PL/SQL areas. Monitoring the library cache is important to determine whether it is necessary to resize Oracle's shared pool.
Each entry in the oraDbLibraryCacheTable represents a given library cache within a current database instance on the node. Each entry is indexed first by rdbmsDbIndex, and then by oraDbLibraryCacheIndex; thus, there will normally be a one-to-many relationship between an rdbmsDbTable entry and corresponding oraDbLibraryCacheTable entries. (For details about rdbmsDbIndex, see Appendix D, "Interpreting Variables of the Public RDBMS MIB") The current value of each oraDbLibraryCacheTable variable is retrieved directly from a corresponding field in the V$LIBRARYCACHE table for that library cache within that database instance.
Table A-4 lists each variable of the oraDbLibraryCacheTable and its corresponding object ID.
INTEGER (1..2147483647)
read-only
A unique integer for each row of the oraDbLibraryCacheTable.
8 (only)
very important
oraDbLibraryCacheNameSpace
not applicable
DisplayString
read-only
Indicates the namespace of the V$LIBRARYCACHE table to which this row is related. The value is retrieved from the value of NAMESPACE in V$LIBRARYCACHE.
0 - 30 characters
important
oraDbLibraryCacheIndex
simple string
Counter32
read-only
Indicates the number of times, since database instance startup, that the system requests handles to library objects in this namespace. The value of oraDbLibraryCacheGets is retrieved from the value of GETS in V$LIBRARYCACHE.
0 - 500,00 per day
important
oraDbLibraryCacheGetHits
counter
Counter32
read-only
Indicates the number of times, since database instance startup, that the handles are already allocated in the cache. The value of oraDbLibraryCacheGetHits is retrieved from the value of GETHITS in V$LIBRARYCACHE.
0 - 4294967295
less important
oraDbLibraryCacheGets
counter
Counter32
read-only
Indicates the number of times, since database instance startup, that the system issues pin requests in order to access objects in the cache. The value of oraDbLibraryCachePins is retrieved from the value of PINS in V$LIBRARYCACHE.
oraDbLibraryCachePins is used to calculate the following database instance performance ratio: library cache miss ratio.
0 - 4294967295
less important
oraDbLibraryPinHits, oraDbLibraryCacheReloads
counter
Counter32
read-only
Indicates the number of times, since database instance startup, that the objects the system is pinning are already allocated and initialized in the cache. The value of oraDbLibraryCachePinHits is retrieved from the value of PINHITS in V$LIBRARYCACHE.
0 - 4294967295
important
oraDbLibraryCachePins
counter
Counter32
read-only
Indicates the number of times, since database instance startup, that library objects have to be reinitialized and reloaded with data because they have been aged out or invalidated. The value of oraDbLibraryCacheReloads is retrieved from the value of RELOADS in V$LIBRARYCACHE.
oraDbLibraryCacheReloads is used to calculate the following database instance performance ratio: library cache miss ratio.
0 - 4294967295
important
oraDbLibraryCachePins
counter
Counter32
read-only
Indicates the number of times, since database instance startup, that non-persistent library objects (like shared SQL areas) have been invalidated. The value of oraDbLibraryCacheInvalidations is retrieved from the value of INVALIDATIONS in V$LIBRARYCACHE.
0 - 4294967295
less important
none
counter
The LibraryCacheSum table tracks for all library caches in a database instance as a whole the same information that the LibraryCache table tracks for the caches individually. It is primarily a convenience.
Counter32
read-only
Indicates the number of times, since database instance startup, that the system requests handles to library objects in this namespace. The value of oraDbLibraryCacheSumGets is derived from the value of GETS in V$LIBRARYCACHE.
0 - 500,00 per day
important
oraDbLibraryCacheSumGetHits
counter
Counter32
read-only
Indicates the number of times, since database instance startup, that the handles are already allocated in the cache. The value of oraDbLibraryCacheSumGetHits is derived from the value of GETHITS in V$LIBRARYCACHE.
0 - 4294967295
less important
oraDbLibraryCacheSumGets
counter
Counter32
read-only
Indicates the number of times, since database instance startup, that the system issues pin requests in order to access objects in the cache. The value of oraDbLibraryCacheSumPins is derived from the value of PINS in V$LIBRARYCACHE.
oraDbLibraryCacheSumPins is used to calculate the following database instance performance ratio: library cache miss ratio.
0 - 4294967295
less important
oraDbLibraryPinHits, oraDbLibraryCacheSumReloads
