Locking Conflicts panel

This panel shows existing Db2 locking contentions. It provides information about the owners and waiters currently involved in locking conflicts.

A locking conflict exists when a Db2 thread owning a resource causes another Db2 thread to wait. In general, when Db2 cannot satisfy a request for the resource, the requester will be suspended.

A suspended lock resource always has an owning thread. Multiple threads may be waiting for the same resource. It may also have one or more global owners that have global interest in the resource.

When S mode is used in data sharing environment, lock resources that are waited by a local thread will be displayed. All global owners and all local threads that are involved in this locking conflict are displayed.

When G mode is used in data sharing environment, lock resources that are waited by a local or remote thread will be displayed. All the global owners and all local and remote threads that are involved in the locking conflict are displayed.

The plan names of all threads for which the elapsed time exception has tripped are highlighted. For more information about current thread exceptions, type E.A on the top line of the panel to display the Exception Messages for Thread Exceptions panel.


________________ ZLOCKC   VTM     O2       V550.#P SAD  G 11/05/13 14:00:19 2 
>       Help PF1      Back PF3      Up PF7      Down PF8       Zoom PF11       
> L.                                                                           
===============================================================================
>                             LOCKING CONFLICTS                                
                                                                               
 XLOK                                                                          
+Stat Plan     Corrid       Type Lvl Resource                                  
+---- -------- ------------ ---- --- ------------------------------------------
+Owned by Subsystem SAC     ROW      DB=DSNDB04  PS=RLOCKTSG PG=00000002/01    
+Owned by Subsystem SAD     ROW      DB=DSNDB04  PS=RLOCKTSG PG=00000002/01    
+ OWN DSNESPCS MIS          ROW    X DB=DSNDB04  PS=RLOCKTSG PG=00000002/01    
+WAIT DSNESPCS MIS          ROW    U DB=DSNDB04  PS=RLOCKTSG PG=00000002/01    
===============================================================================

Highlighting

OMEGAMONĀ® for Db2 PE highlights some fields in this panel to draw your attention to their current status:
Table 1. Highlighted fields in Locking Conflicts panel
Field Exception Reason
Plan ETIM Elapsed time is high.

Navigation

For additional information about
  • a lock owner, move the cursor to the lock owner line and press F11 (Zoom).
  • a lock waiter, move the cursor to the lock waiter line and press F11 (Zoom).
  • other topics, use the PF keys.
Note: Thread information is not available if the thread is owned by the other member of the data sharing group.

Fields

The output lines are displayed in descending order, with those reflecting the greatest degree of conflict displayed first.

Stat
The status of the thread can be one of the following:
  • OWN indicates that the thread is a lock owner.
  • WAIT indicates that the thread is suspended because the lock it requested is owned by another thread.
Plan
The name of the Db2 plan that is currently active in this thread.
Corrid
The Db2 correlation identifier for the thread involved in the locking conflict.
Type
The type of lock that is owned or requested and is unavailable.
Lvl
The level at which the lock is owned or was requested. The level of a lock requested is frequently the reason for lock suspensions.
Resource
Identifies the resource that is currently locked by the lock owner, or the lock resource causing the lock to be suspended. The resource varies depending upon the type of lock held.
Note: DB=database name can be represented as a DBID=identifier, which is the decimal identifier of the database. PSID=identifier can be represented as PSID=identifier, which is the decimal identifier of the table space. HEX values are displayed for lock resources if the resource is owned by a thread on a remote LPAR, and no OMPE task is available from that LPAR, or XCF is not set up correctly. If the owner is a thread running on some other member of the data sharing group, the Db2 subsystem name is displayed.
This field displays the following resources:
Lock Type
Resource
ACSC
Accelerator Services commands lock
ALBP
Alter buffer pool lock
BIND
Autobind/remote bind lock
BMBA
Buffer manager SCA MBA L-lock
BPPS
Buffer manager pageset RP P-lock
CCAT
CATMAINT convert catalog lock
CDBL
Compress dictionary build lock
CDIR
CATMAINT convert directory lock
CDRN
Cursor Stability drain lock
CMDS
Db2 Command Serialization lock
CMIG
CATMAINT migration lock
COLL
Collection lock
DBEX
Database exception LPL/GRECP lock
DBXU
Database exception update lock
DGTT
DGTT URID lock
DPAG
Db2 pageset page lock
DPLK
32 K Desperation Pool lock
DSET
Partitioned lock
DTBS
Database lock
GRBP
Group buffer pool start/stop lock
HASH
Hash anchor lock
IEOF
Index end of file lock
IPAG
Index page lock
LBLK
LOB lock
LPLR
LPL Recovery lock
MDEL
Mass delete lock
PALK
Partition lock
PBPC
Group buffer pool castout P-lock
PCDB
DDF CDB P-lock
PDBD
DBD P-lock
PDSO
Pageset or partition pageset open lock
PITR
Index manager tree P-lock
PPAG
Page P-lock
PPSC
Pageset/partition level castout P-lock
PPSP
Pageset/partition P-lock
PRLF
RLF P-lock
PSET
Pageset lock
PSPI
Pageset piece lock
RDBD
Repair DBD Test/Diagnoes lock
RDRN
Repeatable Read drain lock
RGDA
Retry Getpg During Abort
ROW
Row lock
RSTR
SCA access for restart/redo lock
SDBA
Start/stop lock on DBA tabs
SENV
SYSENV serialization lock
SKCT
Skeleton cursor table lock
SKPT
Skeleton package table lock
SPRC
Sys Level PIT Recovery lock
SREC
Log range lock
TABL
Table lock
UIDA
Util I/O Damage Assessment
UNDT
Undetermined lock
UTEX
Utility exclusive execution lock
UTID
Utility UID lock
UTSE
Utility serialization lock
WDRN
Write drain lock
XMLK
XML lock
UTOB
Utility object lock
DBDL
DBD load lock
IXKY
Index key lock
HPSP
Header page bucket or Stored Proc Cmd lock