DB2 UDB for z/OS Version 8 Performance Topics - IBM Redbooks

Storage heading Description
TOTAL AGENT LOCAL STORAGE The amount of storage allocated for agent-related local storage for
operations such as sort.
TOTAL AGENT SYSTEM STORAGE Storage consumed by the various system agents, prefetch, castout, and
deferred write engines.
NUMBER OF PREFETCH ENGINES Number of engines used for sequential, list, and dynamic prefetch
NUMBER OF DEFERRED WRITE ENGINES Number of engines used for deferred write operations
NUMBER OF CASTOUT ENGINES Number of engines used for data sharing castout engines
NUMBER OF GBP WRITE ENGINES Number of write engines used for group buffer pools
NUMBER OF P-LOCK/NOTIFY EXIT
ENGINES
Number of engines used for data sharing P-lock or notify exit conditions
TOTAL AGENT NON-SYSTEM STORAGE This is a derived field:
TOTAL AGENT LOCAL STORAGE - TOTAL AGENT SYSTEM
STORAGE
TOTAL NUMBER OF ACTIVE USER
THREADS
Includes all active allied threads and the current number of active
DBATs (derived from IFCID 225 and 001)
RDS OP POOL Total storage for RDS operations pool used for sort, prepare, and other
common functions. In V8 it is only used for binding (prepare)
RID POOL Storage used by list prefetch, multiple index access processing, and
hybrid joins; maximum size specified by DSNZPARM MAXRBLK
PIPE MANAGER SUB POOL Storage allocated to pipe manager for parallel query operations
LOCAL DYNAMIC STMT CACHE CNTL
BLKS
THREAD COPIES OF CACHED SQL
STMTS
Storage for local dynamic statement cache blocks
Storage used for the local dynamic statement cache pool
IN USE STORAGE The amount of storage used for thread copies in the local cache storage
pool. This is a subset of the total allocated storage for THREAD
COPIES OF CACHED SQL STMTS
STATEMENTS COUNT Number of SQL statements in cached pools
HWM FOR ALLOCATED STATEMENTS A statistics interval high water mark of allocated storage for thread
copies in the local cache storage pool
STATEMENT COUNT AT HWM The number of statements in the local cache storage pool at high
storage time
DATE AT HWM Date at high water mark for storage
TIME AT HWM Timestamp at high water mark for storage
BUFFER & DATA MANAGER TRACE TBL Storage used for Buffer and Data Manager trace tables
TOTAL FIXED STORAGE Total amount of long-term page fixed storage
TOTAL GETMAINED STACK STORAGE Total GETMAINed storage allocated for program stack use
STORAGE CUSHION Storage reserved to allow DB2 to complete critical functions while
short-on-storage. This includes the contract warning cushion, storage
reserved for must-complete operations, and storage for MVS use.
Appendix B. The DBM1 storage map 395