db2 10 memory management uk db2 user group june 2013 [read-only]

The Information Management Specialists

Memory Management in

DB2 10 for z/OS

Julian Stuhler

UK DB2 GUIDE Meeting, June 2013


Acknowledgements

• John Campbell

• Michael Dewert

• James Gill


Agenda

• Introduction

• What’s Changed & Why?

• What Does It Mean for Me?

• Summary & Questions

Win a limited edition 30th

Anniversary DB2 Geek T-Shirt

for asking me a question!


Introduction

• Julian Stuhler� Director and Principal Consultant at Triton

Consulting

� 25 years DB2 experience, 20 as a consultant working with customers in UK, Europe and the US

� IBM Gold Consultant since 1999

� IBM Information Champion

� IDUG Past President

� Author of IBM Redbooks, white papers and more recently “flashbooks”

� Designer of IBM’s DB2 10 Business Value Assessment Estimator Tool


What’s Changed and Why?

The Need for Scalability


The Need for Scalability

• IT volumes continue to increase� More applications

� More data

� More transactions

• Performance is ever more important� Customers need to support workload growth without a drop-off in

performance

• Availability is ever more important� Pressure to reduce both planned and unplanned outages

• End result: each DB2 environment is being asked to work harder, with less downtime

• Every DB2 release attempts to push back these boundaries, but major progress has been made in DB2 10


DB2 Storage Usage – DBM1 storage

below the bar

0 231

(2GB)

232

(4GB)

“The Bar”

224

(16MB)

“The Line”

Typically 800 – 1900 MB

Available to DB2

Typically 7 – 9 MB

Available to DB2


Virtual Storage Enhancements

• V8 began a major project to transform DB2 into a 64-bit RDBMS� Laid the groundwork and provided

some scalability improvements but a lot of DBM1 objects remained below the 2GB bar

• DB2 9 improved things a little, but only by another 10-15% for most customers� Practical limit of 300-500 threads per

DB2 subsystem

• DB2 10 moves 80-90% of the remaining objects above the bar, resulting in 5-10x improvement in threads per subsystem (CM)


Virtual Storage Enhancements

All storageEDMPool

Thread StorageDataset Storage

Castout buffersCompression Dict

DBD CacheGlobal DSCRIDPOOL

SORTPOOL

CT + PTThread StorageDataset Storage



SORTPOOL

SKCT + PT

(Pointers)Dataset Storage



SORTPOOLSKCT + PT

CT + PTThread

V7 V8 V9 V10


Real Storage Enhancements

• For prior releases, z/OS always managed DB2 bufferpool pages as 4K frames

• Move to 64-bit architecture made much larger buffer pools viable� Bufferpools can use many

millions of pages

� Increased z/OS overheads for page management

DB2 9 Buffer Pool

z/OS Storage

4K

Pages

4K

Pages


Real Storage Enhancements

• DB2 10 introduces support for 1MB pages to reduce z/OS page management overheads� Needs z10/z196/zEC12 server

� Needs bufferpool to be defined with PGFIX=YES

� z/OS sysprogs must partition real storage between 4K and 1MB frames (IESYSnn in PARMLIB, needs IPL) so wait until DB2 10 is bedded in

• Key part of potential DB2 10 CPU reduction � Customer testing during beta

program showed CPU reductions of 0-6% with this feature enabled

DB2 10 Buffer Pool

z/OS Storage

4K

Pages

1MB

Pages


What Does It Mean For Me?


Real Storage Availability

• DB2 10 removes most virtual storage constraints, but you need sufficient real storage to back any increased virtual storage usage� Paging will still kill you in a 64-bit

environment, should be near zero

• Plan on additional 10-30% real memory for DB2 following migration from DB2 9� Most customers will be at lower end of this range, but more will

be required once you start using some DB2 10 capabilities.

� Skip migration customers will need more



• Insufficient real storage to back usage of virtual leads to paging activity

• It is critical to ensure that page-in activity (aka “demand paging”) for DB2 address spaces is minimised (near zero)� No expanded storage in 64-bit environment, all paging is to disk (AUX)

� Any page-in operation is very expensive in performance terms compared to page hit in real storage

� Note that page-out operations are normal for rarely-used pages and not usually a cause for concern

• Real storage shortages can have serious impact on stability of overall system� If all AUX is consumed, LPAR goes into wait state and may fail

� Can lead to long system dump processing times, with high risk of system-wide slowdowns and incomplete dumps



• You also need to allow approx. 16GB for DB2 dump requirement (twice the

8GB value recommended for DB2 8 and 9)

� MAXSPACE parameter defines max amount of virtual storage for SVC dump –

z/OS default is 500MB

� Some customer horror stories due to insufficient storage being available for

dumps

• Good news if you’re on a z196, as the “technology dividend” means that

cost per GB is around 75% less than for a z10

� Cheaper still for zEC12

• Many customers are already running lean on real storage even under V9,

and are building real storage increase costs into their DB2 10 financial

justifications


Real Storage Monitoring

• Statistics IFCID 225 has long been vital for DB2 storage monitoring� Part of Statistics Class 1 trace since PQ99658, so now enabled by default

• Once DB2 10 is implemented in your environment, focus should change from virtual to real storage monitoring

• PM24723 and PM37647 introduce important real storage monitoring and contraction enhancements� ICFID 225 enhanced with new fields to externalise real and auxiliary storage

consumption for storage objects in private, shared, and common areas above the bar (see additional information at end of presentation)

� Introduces two new DSNZPARMs to tell DB2 if and how to release any unused real storage (REALSTORAGE_MANAGEMENT) and specify upper limit on DB2 real storage usage (REALSTORAGE_MAX) – see next slide

� Some increase in MSTR CPU due to storage monitoring. Make sure PTFs for z/OS APAR OA37821 and corresponding DB2 APAR PM49816 are also applied –see later


Real Storage Monitoring

• Opaque DSNZPARMs introduced by PM24723 and PM37647

• REALSTORAGE_MANAGEMENT� ON – Unused backed real frames discarded when possible (CPU overhead)

� OFF – DB2 will only discard unused frames when critical real storage or auxiliary storage usage is detected

� AUTO (default) – DB2 will discard unused frames when the system begins to page

� Recommended value = AUTO

� DSNV516I and DSNV517I written when DB2 enters and exits real storage contraction mode

• REALSTORAGE_MAX� Hard limit on real and auxiliary storage used by DB2 subsystem – DB2 will terminate if limit

reached

� Valid values: NOLIMIT (default), 1 – 65,535 (GB)

� Recommended value = 2 x amount of real and auxiliary storage that the subsystem might reasonably consume

� DSNS003I written when DB2 approaches the threshold and DSNS004I written to indicate relief from this condition


Real Storage – Other Issues

• Ensure PTFs for z/OS APAR APAR OA37821 and corresponding DB2 APAR PM49816 are applied� Fixes MSTR CPU issue associated with MVS COUNTPAGES function used for real storage

monitoring (introduced by our good friend PM24723)

� Especially noticable where more than one DB2 subsystem resides on same LPAR,or on an idle system

� Needs IPL to implement z/OS fix

� Both APARs marked as HIPER – you are strongly advised to implement the associated PTFs before migrating to DB2 10 in any production environments

• What about CONTSTOR and MINSTOR?� Enabling these ZPARMs in previous releases allowed you to spend a little more CPU in

exchange for improved virtual storage utilisation

� Both ZPARMs apply to 31-bit storage only, so are less important in DB2 10

� Recommendation is CONTSTOR=MINSTOR=NO once you have proven VSCR in DB2 10


Other Limiting Factors

• DBM1 Virtual Storage should no longer be an issue, but other limiting factors on vertical scalability still remain

� ESQA/ECSA (31-bit) storage

� Active log write contention (LC19)

� SMF volumes (DB2 10 SMF compression can help)


Use New DB2 10 Features

• Only consider use of new features when you are sure you have fully considered all the previous items and DB2 10 is properly “bedded in”

• Remember that some VSCR enhancements are available in CM, but you need package rebind to get maximum benefits



• Exploit 1MB real storage frames� Needs PGFIX=YES, but many customers still haven’t exploited

this feature in their DB2 8 and DB2 9 systems despite significant potential CPU savings (up to 6% seen)

� PGFIX=YES benefits dependent on I/O rate, and you need to back pools 100% with real storage (scary if you’re already running lean on real storage availability)

� 1MB page frames specified by LFAREA in IEASYSnn parmlib member, and need IPL to implement► Use /DISPLAY VIRTSTOR,LFAREA after implementation to ensure sizing

is OK, as conversion between 4K and 1MB frames costs CPU

� Ensure you are up to date on z/OS maintenance before enabling


DB2 10 Real Storage Enhancements

• 1MB page frame support for buffer pools� CPU savings of up to 4% by reducing z/OS

page management overheads for big BPs► DB2 BPs can be up to 1TB total in DB2 9 and

10, with limit of 2x available real storage

� z/OS sysprogs must partition real storage between 4K and 1MB frames► LFAREA parm in IEASYSnn PARMLIB

(expressed in %, MB or GB, 80% max)

► Need IPL to change LFAREA, so ensure DB2 10 is properly “bedded in” before implementing!


DB2 10 Real Storage Enhancements

• z/OS can decompose 1MB pages into 256 x 4KB pages, or recombine 4KB pages into 1MB pages if SOS condition occurs� Costs CPU and elapsed time so should be avoided by setting LFAREA appropriately

LFAREA

Decompose / recombine


Tuning – Setting LFAREA

• Sizing guideline� Review BPs and set PGFIX=YES where suitable

► Ensure sufficient real storage to back BP

► See BP tuning section earlier

� Set LFAREA = SUM (page-fixed BPs) + 10%► Assumes DB2 is only major user of 1MB page frames, but allows 10% “wriggle

room”

� Verify sizing is correct (after IPL and DB2 BP allocation!)► /DISPLAY VIRTSTOR,LFAREA (no decomposition)

► -DIS BUFFERPOOL(nn) SERVICE=4 (no 4K pages used for page-fixed buffer pools)

• Review LFAREA whenever BP sizes, page-fix attribute etc is changed� Sysprogs and DBAs must co-ordinate activities (should be BAU!)


Real Storage Monitoring• Monitor use of 1MB page frames used by a specific BP

� -DISPLAY BUFFERPOOL(BPnn) SERVICE=4

� Resultant DSNB999I message shows number of 1MB pages in use

----DBA1 DIS BUFFERPOOL(BP0) SERVICE=4 DBA1 DIS BUFFERPOOL(BP0) SERVICE=4 DBA1 DIS BUFFERPOOL(BP0) SERVICE=4 DBA1 DIS BUFFERPOOL(BP0) SERVICE=4

DSNB401I -DBA1 BUFFERPOOL NAME BP0, BUFFERPOOL ID 0, USE COUNT 246

DSNB402I -DBA1 BUFFER POOL SIZE = 5000 BUFFERS AUTOSIZE = NO 641

ALLOCATED = 5000 TO BE DELETED = 0

IN-USE/UPDATED = 172

DSNB406I -DBA1 PGFIX ATTRIBUTE - 642

CURRENT = NO

PENDING = NO

PAGE STEALING METHOD = LRU

DSNB404I -DBA1 THRESHOLDS - 643

VP SEQUENTIAL = 80

DEFERRED WRITE = 30 VERTICAL DEFERRED WRT = 5, 0

PARALLEL SEQUENTIAL =50 ASSISTING PARALLEL SEQT= 0

DSNB999I -DBA1 DSNB1DBP SERVICE( 4 )OUTPUT

DSNB999I -DBA1 4K PAGES 5000

DSNB999I -DBA1 1M PAGES 0

DSN9022I -DBA1 DSNB1CMD '-DIS BUFFERPOOL' NORMAL COMPLETION


Real Storage Monitoring• Monitor use of 1MB page frames across LPAR

� /DISPLAY VIRTSTOR,LFAREA (needs APAR OA31116)

� IAR019I message shows breakdown of 4KB and 1MB page frames and how much of each is currently available

� HWM usage is also shown – useful for ensuring correct segmentation of 4K and 1MB pages in z/OS

/DISPLAY VIRTSTOR,LFAREA IAR019I 12.31.04 DISPLAY VIRTSTOR

SOURCE = GS TOTAL LFAREA = 1024MLFAREA AVAILABLE = 1023M LFAREA ALLOCATED (1M) = 10M LFAREA ALLOCATED (4K) = 2M MAX LFAREA ALLOCATED (1M) = 10M MAX LFAREA ALLOCATED (4K) = 2M

Current / HWM LFAREA allocated for 4KB pages

(pages decomposed)


Use New DB2 10 Features• Possibility for less DB2

subsystems (and possibly less LPARs) in a data sharing environment � Lower data sharing overhead

� Less systems to manage / maintain

� Minimum of 4 members / 2 LPARs still recommended for high availability



• More space for performance critical storage objects such as dynamic statement cache� Improve DSC hit ratio and reduce CPU accordingly

� Potential for significant MAXKEEPD increase is a key part of the overall DB2 10 value proposition for SAP customers

• Potential to reduce CPU cost through more use of persistent threads with RELEASE(DEALLOCATE) � CICS protected entry threads

� DB2 10 High-Performance DBATs

� Remember trade-off on BIND/DDL concurrency with use of RELEASE(DEALLOCATE)

• Don’t forget that you’ll need to allocate additional real storage to back any increases above!


The Future

• IBM announced zEnterprise EC12 in August 2012� 12th generation processor, running at 5.5GHz

� Up to 101 configurable processors per server

� Flash express – up to 6.4TB of SSD as a new memory tier between RAIM and disk

• Several new memory-related features planned � DB2 code backed by 1MB page frames

� Pageable 1MB page frames (no need for PGFIX=YES)

� Support for (non pageable) 2GB page frames

� Support for Flash express

• IBM statement of direction for DB2 exploitation of these features in a future release ☺


Summary & Questions


Summary

• Make sure you have enough real storage before upgrading to DB2 10

• Change your focus from monitoring virtual storage to monitoring real storage

• If you are scaling vertically or consolidating subsystems, be aware of other limiting factors that were previously invisible but may now come to bite you

• Once you’ve addressed ALL of the above, start to make use of the new DB2 10 storage-related features� Remember to add more real storage as required in order to prevent

paging


Feedback / Questions

Julian Stuhler – [email protected]

Triton Consulting

25 Bank Plain

Norwich NR2 4SF

www.triton.co.uk


Additional Information


Real Storage Monitoring – New IFCID

225 CountersADDRESS SPACE SUMMARY ADDRESS SPACE SUMMARY ADDRESS SPACE SUMMARY ADDRESS SPACE SUMMARY –––– DBM1 DBM1 DBM1 DBM1

EXTENDED REGION SIZE (MAX) : 1587544064 24EXTENDED REGION SIZE (MAX) : 1587544064 24EXTENDED REGION SIZE (MAX) : 1587544064 24EXTENDED REGION SIZE (MAX) : 1587544064 24----BIT LOW PRIVATE : 221184 BIT LOW PRIVATE : 221184 BIT LOW PRIVATE : 221184 BIT LOW PRIVATE : 221184

24242424----BIT HIGH PRIVATE : 450560 31BIT HIGH PRIVATE : 450560 31BIT HIGH PRIVATE : 450560 31BIT HIGH PRIVATE : 450560 31----BIT EXTENDED LOW PRIVATE : 69603328 BIT EXTENDED LOW PRIVATE : 69603328 BIT EXTENDED LOW PRIVATE : 69603328 BIT EXTENDED LOW PRIVATE : 69603328

31313131----BIT EXTENDED HIGH PRIVATE : 38600704 CURR HIGH ADDR 24BIT EXTENDED HIGH PRIVATE : 38600704 CURR HIGH ADDR 24BIT EXTENDED HIGH PRIVATE : 38600704 CURR HIGH ADDR 24BIT EXTENDED HIGH PRIVATE : 38600704 CURR HIGH ADDR 24----BIT PRIV REGION : X’0003C000’ BIT PRIV REGION : X’0003C000’ BIT PRIV REGION : X’0003C000’ BIT PRIV REGION : X’0003C000’

CURR HIGH ADDR 31CURR HIGH ADDR 31CURR HIGH ADDR 31CURR HIGH ADDR 31----BIT PRIV REGION : X’270E9000’ 31BIT PRIV REGION : X’270E9000’ 31BIT PRIV REGION : X’270E9000’ 31BIT PRIV REGION : X’270E9000’ 31----BIT RESERVED FOR MUST COMPLETE : 158754406 BIT RESERVED FOR MUST COMPLETE : 158754406 BIT RESERVED FOR MUST COMPLETE : 158754406 BIT RESERVED FOR MUST COMPLETE : 158754406

31313131----BIT RESERVED FOR MVS : 25827760 STORAGE CUSHION WARNING TO CONTRACT: 158754406 BIT RESERVED FOR MVS : 25827760 STORAGE CUSHION WARNING TO CONTRACT: 158754406 BIT RESERVED FOR MVS : 25827760 STORAGE CUSHION WARNING TO CONTRACT: 158754406 BIT RESERVED FOR MVS : 25827760 STORAGE CUSHION WARNING TO CONTRACT: 158754406

TOTAL 31TOTAL 31TOTAL 31TOTAL 31----BIT GETMAINED STACK : 4341760 TOTAL 31BIT GETMAINED STACK : 4341760 TOTAL 31BIT GETMAINED STACK : 4341760 TOTAL 31BIT GETMAINED STACK : 4341760 TOTAL 31----BIT STACK IN USE : 3997696 BIT STACK IN USE : 3997696 BIT STACK IN USE : 3997696 BIT STACK IN USE : 3997696

TOTAL 31TOTAL 31TOTAL 31TOTAL 31----BIT VARIABLE POOL : 12836864 TOTAL 31BIT VARIABLE POOL : 12836864 TOTAL 31BIT VARIABLE POOL : 12836864 TOTAL 31BIT VARIABLE POOL : 12836864 TOTAL 31----BIT FIXED POOL : 86016 BIT FIXED POOL : 86016 BIT FIXED POOL : 86016 BIT FIXED POOL : 86016

TOTAL 31TOTAL 31TOTAL 31TOTAL 31----BIT GETMAINED : 1002384 AMOUNT OF AVAILABLE 31BIT GETMAINED : 1002384 AMOUNT OF AVAILABLE 31BIT GETMAINED : 1002384 AMOUNT OF AVAILABLE 31BIT GETMAINED : 1002384 AMOUNT OF AVAILABLE 31----BIT : 1479335936 BIT : 1479335936 BIT : 1479335936 BIT : 1479335936

SYSTEM AGENT STACK STORAGE IN USE : 1234567SYSTEM AGENT STACK STORAGE IN USE : 1234567SYSTEM AGENT STACK STORAGE IN USE : 1234567SYSTEM AGENT STACK STORAGE IN USE : 1234567

TOTAL 64TOTAL 64TOTAL 64TOTAL 64----BIT VARIABLE POOL : 10162176 TOTAL 64BIT VARIABLE POOL : 10162176 TOTAL 64BIT VARIABLE POOL : 10162176 TOTAL 64BIT VARIABLE POOL : 10162176 TOTAL 64----BIT FIXED : 7503872 BIT FIXED : 7503872 BIT FIXED : 7503872 BIT FIXED : 7503872

TOTAL 64TOTAL 64TOTAL 64TOTAL 64----BIT GETMAINED : 438127168 TOTAL 64BIT GETMAINED : 438127168 TOTAL 64BIT GETMAINED : 438127168 TOTAL 64BIT GETMAINED : 438127168 TOTAL 64----BIT PRIVATE FOR STOR MANAG: 1925120 BIT PRIVATE FOR STOR MANAG: 1925120 BIT PRIVATE FOR STOR MANAG: 1925120 BIT PRIVATE FOR STOR MANAG: 1925120

REAL 4K FRAMES IN USE : 20577 AUXILIARY SLOTS IN USE : 41227 REAL 4K FRAMES IN USE : 20577 AUXILIARY SLOTS IN USE : 41227 REAL 4K FRAMES IN USE : 20577 AUXILIARY SLOTS IN USE : 41227 REAL 4K FRAMES IN USE : 20577 AUXILIARY SLOTS IN USE : 41227

64646464----BIT REAL 4K FRAMES IN USE : 12129 64BIT REAL 4K FRAMES IN USE : 12129 64BIT REAL 4K FRAMES IN USE : 12129 64BIT REAL 4K FRAMES IN USE : 12129 64----BIT 4K AUX SLOTS IN USE : 27055 BIT 4K AUX SLOTS IN USE : 27055 BIT 4K AUX SLOTS IN USE : 27055 BIT 4K AUX SLOTS IN USE : 27055

ABOVE VALUE W/O BP STORAGE : 10000 ABOVE VALUE W/O BP STORAGE : 4096ABOVE VALUE W/O BP STORAGE : 10000 ABOVE VALUE W/O BP STORAGE : 4096ABOVE VALUE W/O BP STORAGE : 10000 ABOVE VALUE W/O BP STORAGE : 4096ABOVE VALUE W/O BP STORAGE : 10000 ABOVE VALUE W/O BP STORAGE : 4096

HWM 64HWM 64HWM 64HWM 64----BIT REAL 4K FRAMES IN USE : 43047 HWM 64BIT REAL 4K FRAMES IN USE : 43047 HWM 64BIT REAL 4K FRAMES IN USE : 43047 HWM 64BIT REAL 4K FRAMES IN USE : 43047 HWM 64----BIT AUX SLOTS IN USE : 27059 BIT AUX SLOTS IN USE : 27059 BIT AUX SLOTS IN USE : 27059 BIT AUX SLOTS IN USE : 27059

QW0225CTLP (S) : OFF QW0225CTLS (S) : OFFQW0225CTLP (S) : OFF QW0225CTLS (S) : OFFQW0225CTLP (S) : OFF QW0225CTLS (S) : OFFQW0225CTLP (S) : OFF QW0225CTLS (S) : OFF


Real Storage Monitoring – New IFCID

225 CountersSHARED/COMMON STORAGE SUMMARY SHARED/COMMON STORAGE SUMMARY SHARED/COMMON STORAGE SUMMARY SHARED/COMMON STORAGE SUMMARY

EXTENDED CSA SIZE : 315179008 31EXTENDED CSA SIZE : 315179008 31EXTENDED CSA SIZE : 315179008 31EXTENDED CSA SIZE : 315179008 31----BIT COMMON FIXED POOL : 1122304 BIT COMMON FIXED POOL : 1122304 BIT COMMON FIXED POOL : 1122304 BIT COMMON FIXED POOL : 1122304

31313131----BIT COMMON VARIABLE POOL : 716800 31BIT COMMON VARIABLE POOL : 716800 31BIT COMMON VARIABLE POOL : 716800 31BIT COMMON VARIABLE POOL : 716800 31----BIT COMMON GETMAINED : 79661 BIT COMMON GETMAINED : 79661 BIT COMMON GETMAINED : 79661 BIT COMMON GETMAINED : 79661

64646464----BIT COMMON FIXED POOL : 3641344 64BIT COMMON FIXED POOL : 3641344 64BIT COMMON FIXED POOL : 3641344 64BIT COMMON FIXED POOL : 3641344 64----BIT COMMON VARIABLE POOL : 37748736 BIT COMMON VARIABLE POOL : 37748736 BIT COMMON VARIABLE POOL : 37748736 BIT COMMON VARIABLE POOL : 37748736

64646464----BIT COMMON GETMAINED : 0 64BIT COMMON GETMAINED : 0 64BIT COMMON GETMAINED : 0 64BIT COMMON GETMAINED : 0 64----BIT COMMON FOR STOR MANAG : 1400832 BIT COMMON FOR STOR MANAG : 1400832 BIT COMMON FOR STOR MANAG : 1400832 BIT COMMON FOR STOR MANAG : 1400832

64646464----BIT SHARED VARIABLE POOL : 13545472 64BIT SHARED VARIABLE POOL : 13545472 64BIT SHARED VARIABLE POOL : 13545472 64BIT SHARED VARIABLE POOL : 13545472 64----BIT SHARED FIXED : 3129344 BIT SHARED FIXED : 3129344 BIT SHARED FIXED : 3129344 BIT SHARED FIXED : 3129344

64646464----BIT SHARED GETMAINED : 4220208 64BIT SHARED GETMAINED : 4220208 64BIT SHARED GETMAINED : 4220208 64BIT SHARED GETMAINED : 4220208 64----BIT SHARED FOR STOR MANAG : 2056192 BIT SHARED FOR STOR MANAG : 2056192 BIT SHARED FOR STOR MANAG : 2056192 BIT SHARED FOR STOR MANAG : 2056192

64646464----BIT SHR SYSTEM AGENT STACK (AS) : 268435456 64BIT SHR SYSTEM AGENT STACK (AS) : 268435456 64BIT SHR SYSTEM AGENT STACK (AS) : 268435456 64BIT SHR SYSTEM AGENT STACK (AS) : 268435456 64----BIT SHR SYSTEM AS IN USE : 33554432 BIT SHR SYSTEM AS IN USE : 33554432 BIT SHR SYSTEM AS IN USE : 33554432 BIT SHR SYSTEM AS IN USE : 33554432

64646464----BIT SHR NONBIT SHR NONBIT SHR NONBIT SHR NON----SYSTEM AS : 805306368 64SYSTEM AS : 805306368 64SYSTEM AS : 805306368 64SYSTEM AS : 805306368 64----BIT SHR NONBIT SHR NONBIT SHR NONBIT SHR NON----SYSTEM AS IN USE : 1048576 SYSTEM AS IN USE : 1048576 SYSTEM AS IN USE : 1048576 SYSTEM AS IN USE : 1048576

SHARED MEMORY OBJECTS : 5 SHARED MEMORY OBJECTS : 5 SHARED MEMORY OBJECTS : 5 SHARED MEMORY OBJECTS : 5

64646464----BIT SHARED MEMORY PAGES : 117440512 HWM 64BIT SHARED MEMORY PAGES : 117440512 HWM 64BIT SHARED MEMORY PAGES : 117440512 HWM 64BIT SHARED MEMORY PAGES : 117440512 HWM 64----BIT SHARED BYTES : 481036337152 BIT SHARED BYTES : 481036337152 BIT SHARED BYTES : 481036337152 BIT SHARED BYTES : 481036337152

64646464----BIT SHARED PAGES BACKED IN REAL : 9395 AUX SLOTS USED FOR 64BIT SHARED PAGES BACKED IN REAL : 9395 AUX SLOTS USED FOR 64BIT SHARED PAGES BACKED IN REAL : 9395 AUX SLOTS USED FOR 64BIT SHARED PAGES BACKED IN REAL : 9395 AUX SLOTS USED FOR 64----BIT SHARED : 5385 BIT SHARED : 5385 BIT SHARED : 5385 BIT SHARED : 5385

64646464----BIT PAGES PAGED IN FROM AUX STO : 5317 64BIT PAGES PAGED IN FROM AUX STO : 5317 64BIT PAGES PAGED IN FROM AUX STO : 5317 64BIT PAGES PAGED IN FROM AUX STO : 5317 64----BIT PAGES PAGED OUT TO AUX STO : 41577BIT PAGES PAGED OUT TO AUX STO : 41577BIT PAGES PAGED OUT TO AUX STO : 41577BIT PAGES PAGED OUT TO AUX STO : 41577

64646464----BIT SHR STG REAL 4K FRMS IN USE : 12344459 64BIT SHR STG REAL 4K FRMS IN USE : 12344459 64BIT SHR STG REAL 4K FRMS IN USE : 12344459 64BIT SHR STG REAL 4K FRMS IN USE : 12344459 64----BIT SHR STG 4K AUX SLTS IN USE : 512BIT SHR STG 4K AUX SLTS IN USE : 512BIT SHR STG 4K AUX SLTS IN USE : 512BIT SHR STG 4K AUX SLTS IN USE : 512

64646464----BIT STK STG REAL 4K FRMS IN USE : 12345789 64BIT STK STG REAL 4K FRMS IN USE : 12345789 64BIT STK STG REAL 4K FRMS IN USE : 12345789 64BIT STK STG REAL 4K FRMS IN USE : 12345789 64----BIT STK STG 4K AUX SLTS IN USE : 256BIT STK STG 4K AUX SLTS IN USE : 256BIT STK STG 4K AUX SLTS IN USE : 256BIT STK STG 4K AUX SLTS IN USE : 256

64646464----BIT COM STG REAL 4K FRMS IN USE : 12345123456789 64BIT COM STG REAL 4K FRMS IN USE : 12345123456789 64BIT COM STG REAL 4K FRMS IN USE : 12345123456789 64BIT COM STG REAL 4K FRMS IN USE : 12345123456789 64----BIT COM STG 4K AUX SLTS IN USE : 1234555555BIT COM STG 4K AUX SLTS IN USE : 1234555555BIT COM STG 4K AUX SLTS IN USE : 1234555555BIT COM STG 4K AUX SLTS IN USE : 1234555555

SERVICE INFORMATION:SERVICE INFORMATION:SERVICE INFORMATION:SERVICE INFORMATION:

QW0225_WARN : 0 QW0225_REALAVAIL : 0QW0225_WARN : 0 QW0225_REALAVAIL : 0QW0225_WARN : 0 QW0225_REALAVAIL : 0QW0225_WARN : 0 QW0225_REALAVAIL : 0

QW0225_REALAVAILLO : 0 QW0225_REALAVAILOK : 0QW0225_REALAVAILLO : 0 QW0225_REALAVAILOK : 0QW0225_REALAVAILLO : 0 QW0225_REALAVAILOK : 0QW0225_REALAVAILLO : 0 QW0225_REALAVAILOK : 0

QW0225_ESQAS : 0 QW0225_ESQA_ALLOC : 0QW0225_ESQAS : 0 QW0225_ESQA_ALLOC : 0QW0225_ESQAS : 0 QW0225_ESQA_ALLOC : 0QW0225_ESQAS : 0 QW0225_ESQA_ALLOC : 0

QW0225_ESQA_HWM : 0 QW0225_ECSA_ALLOC : 0QW0225_ESQA_HWM : 0 QW0225_ECSA_ALLOC : 0QW0225_ESQA_HWM : 0 QW0225_ECSA_ALLOC : 0QW0225_ESQA_HWM : 0 QW0225_ECSA_ALLOC : 0

QW0225_ECSA_HWM : 0 QW0225_ECSA_CONV : 0QW0225_ECSA_HWM : 0 QW0225_ECSA_CONV : 0QW0225_ECSA_HWM : 0 QW0225_ECSA_CONV : 0QW0225_ECSA_HWM : 0 QW0225_ECSA_CONV : 0

QW0225_CTGP : OFF QW0225_DISC : OFFQW0225_CTGP : OFF QW0225_DISC : OFFQW0225_CTGP : OFF QW0225_DISC : OFFQW0225_CTGP : OFF QW0225_DISC : OFF


Further Reading

• IBM DB2 10 Home Page

� http://www-01.ibm.com/software/data/db2/zos/db2-10/

• White Paper – DB2 10: A Smarter Database for a Smarter Planet

� https://www14.software.ibm.com/webapp/iwm/web/signup.do?source=sw-infomgt&S_PKG=wp-z-db2-smarter

� Also available as part of a “flashbook” - ISBN: 1583473610

• DB2 10 for z/OS Performance Topics Redbook (SG24-7942)

� http://www.redbooks.ibm.com/abstracts/sg247942.html?Open

• IDUG – International DB2 User Group

� http://www.idug.org/

db2 10 memory management uk db2 user group june 2013 [read-only]

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