Explanation of R/SYSWKDB Workfile DB Utilization Summary / Workfile Space Used fields within Sysview for Db2 for z/OS.

Products

• SYSVIEW Performance Management Option for DB2 for z/OS

Issue/Introduction

Question related to Sysview for Db2 for z/OS request R/SYSWKDB - Workfile DB Utilization Summary.

Workfile Space Used (KB) / By All Agents For DGTT / Config is field WFSPC-DGTT-PREF-KB.
Workfile Space Used (KB) / By All Agents Except For DGTT / Config is field WFSPC-PREF-KB.

Sysview for Db2 for z/OS shows a value for WFSPC-DGTT-PREF-KB (134218K) significantly larger than WFSPC-PREF-KB (56758K).

On this subsystem there are only two DGTT preferred workfiles with a max capacity of 128GB.
Whereas there are 30 non DGTT preferred workfiles, each at approximately 2GB.
Would expect to see a much smaller value for WFSPC-DGTT-PREF-KB.

Workfile Space Used (KB) 32768 29695K 49152 190976K
By All Agents For DGTT 0 2745344 0 134218K <<<<<<<<<<
By All Agents Except For DGTT 32768 29695K 49152 56758K >>>>>>>>>>

 

Environment

Release: 20.0
Component: SYSVIEW Performance Management Option for DB2 for z/OS 

Resolution

The identified Sysview for Db2 R/SYSWKDB Workfile DB Utilization Summary fields are the configured space:

Field Name WFSPC-PREF-KB (value 56758K)

Description
TOTAL WORKFILE STORAGE CONFIG (KB)
The total preferred storage (KB) configured for non-DGTT work files in the Workfile Database.

IBM Field Name: QISTWFSTG

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Field Name WFSPC-DGTT-PREF-KB (value 134218K)

Description
TOTAL DGTT STORAGE CONFIG (KB)
The total preferred storage (KB) configured for DGTTs in the Workfile Database.

IBM Field Name: QISTDGTTSTG

Field WFSPC-DGTT-PREF-KB refers to the total DGTT capacity and field WFSPC-PREF-KB refers to the total non-DGTT capacity. 
Using IBM's description of these fields they describe them as total (KB) configured.

Fields WFSPC-DGTT-USED-KB and WFSPC-USED-KB are storage currently used.