Lock Detail Trace - Lock, Unlock, and Change Requests

This section shows the event specific data for Lock, Unlock, and Change Requests.

Format of Lock, Unlock, and Change Requests

The following sample shows the format of the data for these events.

 DURATION=xxxxxxxx STATE=xxxxx XES PROP=x
 RSN CODE=xxxxxxxx RTNCD=xx    XES FORC=x
 aaaaaaaaaaaaaaaaaaaaa         XES ASYN=x
 PARENT  =xxxxxxxx CACHE=xxx
 OWNER   =xxxxxxxx HASH=X'hhhhhhhh'

Field description

The individual fields have the following meaning:

DURATION

The length of time the lock is held. Valid values are shown in Table 1.

Table 1. Lock Duration-IRLM Requests
Duration	Description
INTEREST	Duration used for P-Locks
MANUAL	Varies depending on the ISOLATION parameter
MANUAL+1	Temporary change of consistency level from CS to RR during bind and DDL
COMMIT	Until commit
COMMIT+1	Past commit; applies to locks needed to maintain the position for a cursor opened WITH HOLD
ALLOCATN	Until deallocation
PLAN	For the duration of the plan
UTILITY	For the duration of the utility execution
FREE ALL	Until all locks are freed
N/A	Not applicable for NOTIFY SUSPEND

The duration controls when locks are released. A lock is usually only released when an agent makes an unlock request with a duration longer, or equal to, the longest lock duration the agent specified for the resource.

You can increase lock durations using either a lock request or a change request.

STATE

The state or mode of the lock applied to the resource. Valid values are shown in Table 2.

Table 2. Lock State-IRLM Requests
State	Description
IS	Intent share
IX	Intent exclusive
S	Share
U	Update
SIX	Share with intent exclusive
NSU	Nonshared update
X	Exclusive
N/A	Not applicable for NOTIFY SUSPEND

RTNCD

The return code issued in response to the request. The possible return codes are shown in Table 3.

Table 3. Return Codes-IRLM Requests
Code	Description
0	Successful completion
4	Successful completion, lock state unchanged
8	Unsuccessful completion, system error
12	Unsuccessful completion, logic error in request
16	Unsuccessful completion, request specification not valid

RSN CODE

The reason code issued in response to the request. The reason code is not applicable for lock avoidance.

Fields that are only printed if the Db2 subsystem is a member of a data sharing group

The remaining fields are only printed if the Db2® subsystem is a member of a data sharing group.

aaaaaaaaaaaaaaaaaaaaa

Stands for the lock attributes, which can be:

MODIFY or NMODIFY
GLOBAL or LOCAL
P-LOCK or L-LOCK

PARENT

The parent lock token if one was specified for explicit hierarchical locking. The field is only printed for LOCK REQUESTs.

If this field is not 0, the request applies to a child of a parent that has already been locked.

CACHE

The cached state of a P-Lock. For the state values, refer to Table 2.

This field is only applicable and printed for page set and partition P-Locks.

OWNER

The member name of the owner of a retained lock that caused this request to be denied and the owner of the lock that caused this request to time out. If neither of these conditions exist, this field is not printed.

HASH

The lock hash value.

XES PROP

An indicator whether or not IRLM propagated the request to XES. Possible values are Y(es) or N(o).

XES FORC

An indicator whether or not the lock was requested to be forced to XES. Possible values are Y(es) or N(o).

XES ASYN

An indicator whether or not IRLM sent the request asynchronously to XES. Possible values are Y(es) or N(o).

This field is only printed if XES PROP=Y.