The Buffer Manager PSET/Part P-lock Request section
This section of the report provides information about physical lock (P-lock) activities in group buffer pools.
The Db2® Buffer Manager uses the P-lock mechanism to manage, negotiate, and resolve inter-DB2 R/W interests on a page set or partition level, that is, when programs running on different data sharing group members request incompatible locks on the same resource. The activity counter values are retrieved from IFCID 251.
OMEGAMON XE FOR DB2 PE (V5R4M0) - BUFFER POOL ACTIVITY REPORT PAGE: 1-91
ORDER: BPID-QPAGESET
SORTBY: BPID,ASYNCPAGE TOP: 17 LEVEL: SUMMARY
GROUP: DBE1 LOCATION: PMODBE1 DB2 VERSION: V11
MEMBER: SE11 REQUESTED FROM: NOT SPECIFIED TO: NOT SPECIFIED
SUBSYSTEM: SE11 INTERVAL FROM: 12/04/15 13:32:25 TO: 12/04/15 13:44:27
======= Buffer Manager PSET/Part P-lock Request =======
BPID GBP0 GBP0 GBP0 GBP0 GBP0 GBP0
PSTYPE T T I I I I
QPAGESET DSNDB06 DSNDB04 DSNDB06 DSNDB06 DSNDB06 DSNDB06
SYSTSISS BPTYUNZO DSNADH01 DSNDDH01 DSNDDX02 DSNSFX01
PARTITION 1 0 0 0 0 0
-------------- ---------- ---------- ---------- ---------- ---------- ----------
IRLM func mode
Lock 2 2 2 2 2 2
Unlock 0 0 0 0 0 0
Change 1 0 0 0 0 0
Change P-lock 0 0 0 0 0 0
New held state
IS 0 0 0 0 0 0
IX 0 0 0 0 0 0
S 2 1 1 1 1 1
SIX 1 0 1 1 1 1
NSU 0 0 0 0 0 0
X 0 1 0 0 0 0
denied 0 0 0 0 0 0
Confl. member 0 0 0 0 0 0
New cach.state
IS 0 0 0 0 0 0
IX 0 0 0 0 0 0
S 2 1 1 1 1 1
SIX 1 0 1 1 1 1
NSU 0 0 0 0 0 0
X 0 1 0 0 0 0
denied 0 0 0 0 0 0
Request type
Condition 0 0 0 0 0 0
Restart 0 0 0 0 0 0
Modify 0 0 0 0 0 0
============== ========== ========== ========== ========== ========== ==========
- IRLM func mode
- The number of requests to the data sharing group member's Internal
Resource Lock Manager (IRLM) by lock type for an object. Note that
an object is identified by BPID (buffer pool ID), PSTYPE (object type),
QPAGESET (combination of database and page set), and partition number.
Derived from the Db2 field QW0251IF.
LockrequestsUnlockrequestsChangerequests by a member holding the lock because of a change of interestChange P-lock(short forChange from P-lock Exit) requests by another member causing the P-lock exit of this member
- New held state
- The number of new held P-lock states (the inter-DB2 interest level)
determined for an object. Derived from the Db2 field
QW0251NS.
IS(Intent Shared): This Db2 has R/O interest in the object and one or more other Db2 members have R/W interest.IX(Intent Exclusive): This Db2 has R/W interest in the object and one or more other Db2 members have R/W interest.S(Shared): This Db2 has R/O interest in the object and no other Db2 member has R/W interest.SIX(Shared Intent Exclusive): This Db2 has R/W interest in the object and one or more other Db2 members have R/O interest.NSU(Non-Shared Update): Acts like an X lock, but is only used during P-lock negotiation from an X to an SIX.X(eXclusive): This Db2 has R/W interest in the object. No other Db2 member has declared interest.denied: A request was denied; the object hadChange P-lockactive.
Normally, Db2 holds the P-lock in the cached state (see later in this list). In some special or abnormal cases, the P-lock will not be held in the cached state. It is the actual held state of the P-lock that determines whether the object is GBP-depended. If the held state is
SorX, the object is not GBP-depended. Otherwise, the object is GBP-depended. - Confl. member
- The number of conflicts determined by the IRLM for an object.
(IRLM function code of
Change From P-lock Exitactive). Derived from the Db2 field QW0251DB. - New cach. state
- The number of cached P-lock states (the inter-DB2 interest level)
determined for an object. Derived from the Db2 field
QW0251NC. See also New held state.
ISIXSSIXNSUXdenied
- Request type
- The number of P-lock requests by request type for an object. Derived
from the Db2 field QW0251F1.
Condition: Conditional request.Restart: Restart lock request. Locks retained by a Db2 system are changed from retained to active.Modify: Modify lock request.