Database and Log SHOW commands

SHOW BUFSTATS:

Use this command to see if you need to increase your database buffer pool size. An associated command is SHOW BUFV, but it is less obvious what the output means.

Example output is:

    Database Buffer Pool Statistics:

    Total Buffer Latch Requests:   184217213
    Times Scavenging Required:      1123642  0.61%
    Times Scavenging by Stealing:   1105210  0.60%
    Times Scavenging by Waiting:          0  0.00%
    Times Read Required:            1123574  0.61%
    Cache Hit Percentage:             99.39%

SHow BUFVars:

Shows database buffer pool global variables.

SHOW DBTXNT:

Use this command to displays the database transaction table.

Example output is:

    Open objects:
    name ->AS.Segments<- (sp=0)
    name ->SS.Pools<-    (sp=0)
    name ->SS.Pool.Ids<- (sp=0)
    name ->AF.Clusters<- (sp=0)
    Tsn=0:813772319 --> Valid=1, inRollback=0, endNTA=0, State=2, 
    Index=10, LatchCount=0, SavePoint=0, TotLogRecs=0, TotLogBytes=0, 
    UndoLogRecs=0, UndoLogBytes=0, LogReserve=0, PageReserve=0, 
    Elapsed=346279 (secs), MinLsn=0.0.0, MaxLsn=0.0.0, LastLsn=0.0.0, 
    UndoNextLsn=0.0.0, logWriter=False, backupTxn=False

This is showing that this transaction has 4 database tables open, that the transaction is valid, and that it is not writing log records.

SHOW DBV:

Displays database global attributes.

SHOW DBBACKUPVOLS:

Use this command to get details on the latest full and incremental database backup volumes.

SHOW LOGPINNED:

You can use this command if your logfile is running out of space. The oldest active record in the log is pinning the log. This command will tell you what task owns that oldest record. You could follow this up with SHOW LOGPINNED CANCEL which will cancel whatever is holding the pinned record. This is one of those ‘UPDATE’ SHOW commands that you need to use with extreme care, and preferably after advice from Tivoli. However, if your log is rapidly filling up, will you have time to make that support call? It would be best to investigate and test this command before you need to use it in an emergency. The command is only available in TSM version 5.1.7.0 or above.

SHOW LOGV:

You can use this command to display the recovery log global attributes, but it is less obvious what they all mean.

SHOW LOGstats:

Use this command to see statistics on log usage. An associated command is SHOW LOGRESET This command will RESET the log statistics back to 0.

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