DBAM MIB Tables
The DBAM MIB information provides statistical information for several DBAM subsystems. The MIB information is stored in the following.
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DBAM transaction statistics
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DBAM buffer cache statistics
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DBAM buffer cache I/O statistics
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DBAM translog device I/O statistics
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DBAM checkpoint statistics
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DBAM interval statistics
These tables are held in memory and reflect the lifetime of the information stored. The information can be displayed by using the dirxextop command.
This appendix lists all information stored in these tables.
DBAM Transaction Statistics
The DBAM transaction statistics stores information about transactions, for example DBAM start up time or number of read or update transactions.
| Name | Metric | Description |
|---|---|---|
StartUpTime |
Date |
DBAM start up time stamp. |
Status performance statistics |
Boolean |
Enabled or disabled |
PerformanceStatisticsStartTime |
Date |
Last time stamp when performance statistics were enabled or disabled |
OldestActiveTransId-ReadTransactions |
Counter |
Transaction identifier of the oldest active read transaction |
OldestActiveTransId-UpdateTransactions |
Counter |
Transaction identifier of the oldest active update transaction |
NextTransId |
Counter |
Next transaction identifier |
ActNoReadTransactions |
Counter |
Actual number of read transactions |
ActNoUpdateTransactions |
Counter |
Actual number of update transactions |
ActPercentUpdateTransactions |
Percent |
Percentage of actual update transactions |
TotalNoReadTransactions |
Counter |
Total number of read transactions since DBAM start up time |
TotalNoUpdateTransactions |
Counter |
Total number of update transactions since DBAM start up time |
TotalPercentUpdateTransactions |
Percent |
Percentage of all update transactions |
TotalNoWaitForCheckPointCompletion |
Counter |
Total number of events where an update transaction had to wait for a checkpoint completion |
DBAM Buffer Cache Statistics
The DBAM buffer cache statistics stores information about the DBAM buffer cache, for example paging information.
| Name | Metric | Description |
|---|---|---|
PageAgingUnit |
Counter |
DBAM internal page aging factor |
PreAllocQueueAgingCounter |
Counter |
DBAM internal page aging load factor |
PageReplaceMode |
Percent |
DBAM buffer cache fill ratio for time triggered page replaces |
MaxBufferCacheSize |
MB |
Maximum buffer cache size in megabytes |
ActBufferCacheSize |
MB |
Actual buffer cache size in megabytes |
ActBufferCacheRatio |
Percent |
Actual buffer cache fill ratio in percent |
NoTimeTriggeredPageReplaceRuns |
Counter |
Total number of time triggered page replace runs |
TimeTriggeredPageReplaceExecTime |
Seconds |
Total elapsed time used for time triggered page replace runs |
TimeTriggeredPageReplaceRate |
Seconds/run |
Average rate for time triggered page replace runs |
LastTimeTriggeredPageReplaceExecTime |
Seconds |
Duration of last time triggered page replace run |
NoLevelTriggeredPageReplaceRuns |
Counter |
Total number of level triggered page replace runs |
LevelTriggeredPageReplaceExecTime |
Seconds |
Total elapsed time used for level triggered page replace runs |
LevelTriggeredPageReplaceRate |
Seconds/run |
Average rate for level triggered age replace runs |
NoPagesReplaced |
Counter |
Total number of pages that have been replaced |
TotalNoCreatePageCalls |
Counter |
Total number of new page creation |
TotalNoPageReadCalls |
Counter |
Total number of page read calls |
TotalNoPageReadCacheHits |
Counter |
Total number of cache hits |
TotalReadPageCacheHitRate |
Percent |
Cache hit rate in percent |
DBAM Buffer Cache I/O Statistics
The DBAM buffer cache I/O statistics stores information about buffer cache input and output operations, for example read or write operations to the data device.
| Name | Metric | Descrition |
|---|---|---|
DataDevice-0 NoReadOperations |
Counter |
Total number of read operations from physical DBAM data device 0. All physical DBAM data devices are enumerated from 0 to n. |
DatatDevice-0 ReadDataSize |
MB |
Total amount of data read from the physical DBAM data device 0. |
DataDevice-0 NoWriteOperations |
Counter |
Total number of write operations to physical DBAM data device 0. |
DatatDevice-0 WriteDataSize |
MB |
Total amount of data written to the physical DBAM data device 0. |
AllDataDevices TotalReadTime |
Seconds |
Accumulated time for read operations for all physical data devices |
AllDataDevices AvrgReadTime/Page |
Seconds/page |
Average read time for a page |
AllDataDevices AvrgReadRate |
MB/second |
Average read rate for a page |
DBAM Translog Device I/O Statistics
The DBAM translog device I/O statistics stores information about input and output operations of the transaction logging device, for example information about the active transaction log area.
| Name | Metric | Descrition |
|---|---|---|
ActiveTransLogArea |
Index |
Active translog area ( 0 or 1) |
TransLogArea-0-NoUncheckPointedTransactions |
Counter |
No of uncheckpointed transactions in translog area 0 |
TransLogArea-0-NoUncheckPointedPages |
Counter |
No of uncheckpointed pages in translog area 0 |
TransLogArea-0-NoUncheckPointedPageUnits |
MB |
Size of uncheckpointed pages in translog area 0 |
TransLogArea-0-TransDeviceDataSize |
MB |
Actual size of translog area 0 |
TransLogArea-0-TransDeviceRatio |
Percent |
Actual ratio of translog area 0 |
TransLogArea-1-NoUncheckPointedTransactions |
Counter |
No of uncheckpointed transactions in translog area 1 |
TransLogArea-1-NoUncheckPointedPages |
Counter |
No of uncheckpointed pages in translog area 1 |
TransLogArea-1-NoUncheckPointedPageUnits |
MB |
Size of uncheckpointed pages in translog area 1 |
TransLogArea-1-TransDeviceDataSize |
MB |
Actual size of translog area 1 |
TransLogArea-1-TransDeviceRatio |
Percent |
Actual ratio of translog area 1 |
TranslogDevice NoWriteOperation |
Counter |
Total number of write operations to the translog device |
TranslogDevice TotalWriteSize |
MB |
Total amount of data written to the translog device |
TranslogDevice TotalWriteTime |
Seconds |
Total elapsed time for write operations |
TranslogDevice TransferRate |
MB/second |
Average write rate |
DBAM Checkpoint Statistics
The DBAM checkpoint statistics stores information about DBAM checkpoints, for example information about checkpoint history.
| Name | Metric | Descrition |
|---|---|---|
NoCheckPointOperations |
Counter |
Total number of checkpoint operations |
NoForcedCheckPointOperations |
Counter |
Total number of forced checkpoint operations |
CheckPointHistory[0]. TimeStamp |
Time stamp |
Time stamp of checkpoint |
CheckPointHistory[0]. ExecutionTime |
Seconds |
Duration of checkpoint |
CheckPointHistory[0]. DataSize |
MB |
Amount of data written at checkpoint |
CheckPointHistory[0]. TransferRate |
MB/seconds |
Transfer rate of checkpoint |
TotalCheckPointExecutionTime |
Seconds |
Total elapsed time for checkpoint operations |
TotalCheckPointDataSize |
MB |
Total amount of checkpoint data written |
AverageCheckPointExecutionTime |
Seconds |
Average duration for a checkpoint |
AverageWriteTransferRate |
MB/second |
Average transfer rate of a checkpoint |
DBAM Interval Statistics
The DBAM interval statistics stores information about transactions performed during a specific time frame, for example the number of all transactions performed.
| Name | Metric | Descrition |
|---|---|---|
LastIntervalStatisticTimeStamp |
Time stamp |
Time stamp of statistic |
IntervalStatisticDuration |
Seconds |
Duration of statistic |
NoAllTransactions |
Counter |
Number of transactions during this interval |
NoReadTransactions |
Counter |
Number of read transactions during this interval |
NoUpdateTransactions |
Counter |
Number of update transactions during this interval |
OverallTransactionLoad |
Ops/second |
All transaction load |
ReadTransactionLoad |
Ops/second |
Read transaction load |
UpdateTransactionLoad |
Ops/second |
Update transaction load |
ReadTransaction-AverageDuration |
Seconds |
Average duration of read transactions |
ReadTransaction-AverageWaitTime |
Seconds |
Average wait time of read transaction. The wait time is the time a transaction start needs to get running. |
ReadTransaction-MinDuration |
Seconds |
Minimum duration of a read transaction. |
ReadTransaction-MaxDuration / TimeStamp |
Seconds |
Maximum duration of a read transaction and the time stamp when this event occurred |
ReadTransaction-MaxWaitTime / TimeStamp |
Seconds/Time stamo |
Maximum wait time of a read transaction and the time stamp when this event occurred. |
UpdateTransaction-AverageDuration |
Seconds |
Average duration of update transactions |
UpdateTransaction-AverageWaitTime |
Seconds |
Average wait time of update transactions |
UpdateTransaction-MinDuration |
Seconds |
Minimum duration of an update transaction |
UpdateTransaction-MaxDuration / TimeStamp |
Seconds/Time stamp |
Maximum duration of an update transaction and the time stamp when this event occurred |
UpdateTransaction-MaxWaitTime / TimeStamp |
Seconds/Time stamp |
Maximum wait time of an update transaction and the time stamp when this event occurred |
UpdateTransaction-NoWaitForCheckPointCompl. |
Counter |
Number of events where an update transaction had to wait for checkpoint completion |