IFCID 106 - Data Sharing Parameters

This topic shows detailed information about "Record Trace - IFCID 106 - Data Sharing Parameters".

This block shows the members in a data-sharing group.

DB2 subsystems that share data must belong to a DB2 data sharing group, which runs on a Parallel Sysplex®. A data sharing group is a collection of one or more DB2 subsystems that access shared DB2 data. A Parallel Sysplex is a collection of MVS systems that communicate and cooperate with each other.

Record trace - IFCID 106 - Data Sharing Parameters

The field labels shown in the following sample layout of "Record Trace - IFCID 106 - Data Sharing Parameters" are described in the following section.

                                             DATA SHARING PARAMETERS                                                     
GROUP NAME ......: 'BLANK'               DATA SHARING ENAB:                   NO  MAX # OF MEMBERS :                  248
MEMBER NAME .....: DC11                  IMMEDWRITE FLAG .:                   NO  CONVERSION FACTOR:                  224
RANDOM ATTACH ...:                  YES  PEER RECOVERY ...:                 NONE                                                                                
                                                                                                                         
QWPALVL .........: DSN1210               QWPACOOR ........:                   NO  QWPAASST ........:                   NO

GROUP NAME

The name of the DB2 data sharing group.

The group name encompasses the entire data sharing group and is the basis for the coupling facility structure names.

N/A means this DB2 is not part of a data sharing group.

Install parameter GROUP NAME on panel DSNTIPK, or ZPARM GRPNAME in DSN6GRP.

Field Name: QWPAGRPN

DATA SHARING ENAB

Indicates whether data sharing is enabled.

Field Name: QWPADSHR

MAX # OF MEMBERS

The maximum number of members possible in a data sharing group. This is a constant (248) and is not shown on any installation panel.

Field Name: QWPAMAXM

MEMBER NAME

The member name of this DB2.

N/A means this DB2 is not part of a data sharing group.

Install parameter MEMBER NAME on panel DSNTIPK, or ZPARM MEMBNAME in DSN6GRP.

Field Name: QWPAMBRN

IMMEDWRITE FLAG

Indicates how DB2 updates group buffer pool dependent pages. This is only valid in a data-sharing environment.

Group buffer pool dependent pages can be written to DASD or SYSTEM pagesets.

Values shown are:

NO: DB2 uses normal write activity for updates, this is the default. Pages are written out at, or before phase 2 commit, or at the end of an abend for transactions that have rolled back.
PH1: Pages are written out at, or before phase 1 commit.
If a transaction subsequently rolls back, the pages are updated in the group buffer pool at the end of the rollback and are written out at the end of the abend.
YES: Pages are written out to the coupling facility as soon as the buffer update commits. Pages are written out regardless of whether the update occurs during forward progress or rollback of the transaction.
This option can affect performance due to coupling facility overhead.

Install parameter IMMEDIATE WRITE on panel DSNTIP8, or ZPARM IMMEDWRI in DSN6GRP.

Field Name: QWPAIMMW

CONVERSION FACTOR

The CPU service unit conversion factor for this CPU.

This factor allows conversion CPU time in seconds to a common unit, called service unit (SU). The conversion factor used depends on the machine. Service units allow you to calculate CPU execution times across a data sharing group.

The conversion factor is used as follows:

CP secs * 16,000,000 / Conversion Factor = SUs

SUs * Conversion Factor / 16,000,000 = CP secs

This field does not map to an installation panel.

Field Name: QWPASUCV

RANDOM ATTACH

Specifies a random group attach flag:

N: Not eligible for random group attach.
NOT N: Eligible for random group attach.

This field corresponds to field RANDOM ATTACH on installation panel DSNTIPK. The ZPARM name is RANDOMATT in DSN6GRP.

Field Name: QWPARAND

PEER RECOVERY

Specifies whether this data sharing member is to participate in data sharing peer recovery.

NONE: None.
RECOVER: This member is recovered by a peer member in case it fails.
ASSIST: This member attempts to initiate peer recovery for other failed members. When this member detects a failure, it will attempt to initiate a LIGHT(YES) restart for the failed member if it has not been initiated to recover the retained locks.
BOTH: Both RECOVER and ASSIST options are activated for this member.

Field Name: QWPAPEERREC

QWPACOOR

Shows whether this DB2 member can coordinate parallel processing on other members of the group.

When NO, a query can be processed by this DB2 member only.

When YES, a read-only query running on this DB2 member can be processed in part on other members of the group.

N/A means this DB2 is not part of a data sharing group.

Install parameter COORDINATOR on panel DSNTIPK or ZPARM COORDNTR in DSN6GRP.

Field Name: QWPACOOR

QWPAASST

Shows whether this DB2 member can assist a parallelism coordinator with parallel processing.

When YES, this member is considered an assistant at both bind and run time. To be a viable assistant at run time, both the VPPSEQT and VPXPSEQT buffer pool thresholds of this member must be greater than 0.

N/A means this DB2 is not part of a data sharing group.

Install parameter ASSISTANT on panel DSNTIPK or ZPARM ASSIST in DSN6GRP.

Field Name: QWPAASST

Feedback