DB2 9 for z/OS Planning and
Experiences
Jim Brogan
IBM DB2 Advisor
jambrog@us.ibm.com
Disclaimer and Trademarks
Information contained in this material has not been submitted to any formal IBM review and is
distributed on "as is" basis without any warranty either expressed or implied. Measurements data
have been obtained in laboratory environment. Information in this presentation about IBM's
future plans reflect current thinking and is subject to change at IBM's business discretion. You
should not rely on such information to make business plans. The use of this information is a
customer responsibility.
IBM MAY HAVE PATENTS OR PENDING PATENT APPLICATIONS COVERING SUBJECT
MATTER IN THIS DOCUMENT. THE FURNISHING OF THIS DOCUMENT DOES NOT IMPLY
GIVING LICENSE TO THESE PATENTS.
TRADEMARKS: THE FOLLOWING TERMS ARE TRADEMARKS OR ® REGISTERED
TRADEMARKS OF THE IBM CORPORATION IN THE UNITED STATES AND/OR OTHER
COUNTRIES: AIX, AS/400, DATABASE 2, DB2, e-business logo, Enterprise Storage Server,
ESCON, FICON, OS/390, OS/400, ES/9000, MVS/ESA, Netfinity, RISC, RISC SYSTEM/6000,
iSeries, pSeries, xSeries, SYSTEM/390, IBM, Lotus, NOTES, WebSphere, z/Architecture, z/OS,
zSeries, System z, pureXML
The FOLLOWING TERMS ARE TRADEMARKS OR REGISTERED TRADEMARKS OF THE
MICROSOFT CORPORATION IN THE UNITED STATES AND/OR OTHER COUNTRIES:
MICROSOFT, WINDOWS, WINDOWS NT, ODBC, WINDOWS 95
For additional information see ibm.com/legal/copytrade.phtml
1
V8/V9 Overview
Worldwide Experience in the Field
Key Measurement V8/V7 Comparison
V8/V9 Comparison
PMR Volume
 V8 LOWER
 V9 LOWER
Field APAR
Severity
 V8 Severity 1’s
LOWER
V8 LOWER
 V9 Severity 1’s
LOWER
(No Data Available)
PE Rate
V8 LOWER
V9 LOWER
HIPER Rate
V8 LOWER
V9 LOWER
Multi-System
Outages
DB2 z/OS Announce / End Of Service
 No skip release
 No GA date announced for DB2 z/OS Vx (next)
 No date announced for DB2 z/OS V8 EOS
– won’t occur till after Vx ‘GA’d’
DB2 z/OS Availability Summary
Version
PID
Generally
Available
Marketing
Withdrawal
End of
Service
V4
5695-DB2
November
1995
December
2000
December
2001
V5
5655-DB2
June 1997
December
2001
December
2002
V6
5645-DB2
June 1999
June 2002
June 2005
V7
5675-DB2
March 2001 March 2007
V8
5625-DB2
March 2004
September
2009
TBD
V9
5635-DB2
March 2007
TBD
TBD
June 2008
2008
June
DB2 Connect and DB2 z/OS v9
 MINIMUM requirements for DB2 Connect to work with
DB2 z/OS V9.


V8 FP13, V8.2 FP 6, V9 FP1
The more current the FIXPACs the better.
 DB2 UDB LUW V8 products are OUT OF SUPPORT

would need to purchase extended support
DB2 for z/OS Adoption
 >85% WW Customers are Current
 DB2 V8: Majority have Migrated
– 100% of Top 100
>99% of Top 200
– V7 End of Service:
June 30, 2008
– V8 Withdrawal from Marketing
• Announced: Dec. 2, 2008
• Effective: Sept. 8, 2009
 DB2 9: Climbing Sharply
– About 1/3 of Top 200 customers
– 15% of TOTAL EAST
– 15% of TOTAL NE/UNY (vast majority of DB2 Data Sharing Customers)
Beneficial Activities
 DB2 z/OS V9 Migration Planning Workshop
– When ready to ORDER
 OPEN PMR for Upgrade/Migration
– When your ready to BEGIN
 Stay CURRENT on MAINT
Maintenance
 Sound maintenance strategy is essential for all
customers
– Recommended to exploit CST/RSU process
– Apply 2 to 3 preventative service drops annually
– Exploit Enhanced HOLDDATA to be vigilant on HIPERs
and PEs
– No one-size-fits-all strategy
– Review installation guide and the material supplied to
ensure that RSU only service is installed
– Can enforce installing RSU only service by adding the
SOURCEID (RSU*) option in the supplied APPLY and
ACCEPT jobs
– Note '*' will pull ALL RSUs off of a particular tape
Important CONSIDERATIONs
 WLM Buffer Pool Management
– Maybe NOT yet
 RRF
– caution if data Compressed
 Plan Stability
– SPT01 (64GB limit)
• (8) 3390 mod 9’s, (64) 3390 mod 1’s
– zPARM
– BIND/Rebind
 Converged TEMP Space
 PERFORMANCE
DSNTIJPM(9)
 JP9 shipped with V8 APAR PK31841
 Checks for:
– Check for V8 Sample Database
• V8 job DSNTEJ1*
– Report of user-defined indexes on the DB2 Catalog that reside on
user-managed storage
• On table spaces that will be converted during ENFM
• DSNTIJEN needs modification for their shadow datasets
– DB2 Managed Stored Procedures (SPAS)
• Convert to WLM established stored procedures before migrating
– Plans & Packages bound prior to V4 that need to be rebound
• They will automatically rebind if ABIND = YES or COEXIST
• If ABIND = NO, a -908 will be received at execute time
– Incomplete table space, table, and columns
– Optimization Service Center table format changes required before
migration.
Migrating to DB2 9
 Complete pre-migration checks against DB2 V8 (DSNTIJP9)
– This will be the same as DSNTIJPM delivered with DB2 9
 Check / correct incompatibilities
– The BSDS needs to be expanded to V8 format (DSNJCNVB)
– If not done before migrating to V9, DSNTIJUZ will convert the
BSDS(s)
 Must be on DB2 for z/OS V8 New Function Mode
 Reestablish V8 IVP to test DB2 9 before NFM
 Assess ISV Requirements
– Tools and applications
– Some vendors may add instructions for migration and / or require
maintenance
 Assess the training requirements for your organization
 Establish a project team and project plan
Migrating to DB2 9
 Develop conversion and coexistence goals
– How did your V8 test plans work?
– Reuse and improve upon your experiences
 Establish performance baselines
 Migration occurs in three familiar phases
–
–
–
–
Conversion Mode (CM)
Enable New Function Mode (ENFM)
New Function Mode (NFM)
With more flexibility to move between modes
DB2 9 for z/OS Migration Modes
 Catalog Modes Illustrated
– V8 to DB2 9 NFM
DSNTIJTC
DB2 for z/OS
V8
Migrate
NFM
Install Fallback SPE &
cycle DB2 (all
members if data
sharing)
BSDS reformatted ( V8
DSNJCNVB)
Run DSNTIJP9
Resolve
inconsistencies
V8 Catalog &
incompatibilities
DSNTIJEN
DB2 9
for z/OS
CM
Convert
Can fallback to V8
Data sharing
coexistence support
Most new function
unavailable
DSNTIJNF
DB2 9
for z/OS
ENFM
Primary catalog
migration phase
Most new features
available
Online REORGs of
SYSOBJ &
SYSPKAGE
REORG table spaces
containing tables with
variable length
columns to use RRF
Running DB2 9 code
Start & Load of RTS
Regression testing
Most new function
unavailable
RUNSTATS / REBIND
Catalog V9 State A
Convert
DB2 9
for z/OS
NFM
Catalog V9 State B
Catalog V9 State B
Some CM New Features
 Catalog Modes Illustrated
– V8 to DB2 9 NFM
DSNTIJTC
DB2 for z/OS
V8
Migrate
NFM
Install Fallback SPE &
cycle DB2 (all
members if data
sharing)
BSDS reformatted ( V8
DSNJCNVB)
Run DSNTIJP9
Resolve
inconsistencies
V8 Catalog &
incompatibilities
DSNTIJEN
DB2 9
for z/OS
CM
Can fallback to V8
Convert
DSNTIJNF
DB2 9
for z/OS
ENFM
Convert
DB2 9
for z/OS
NFM
Primary catalog
Most new features
migration phase
available
Data sharing
 Additional 64
bit improvements
coexistence support
Online
REORGs of
REORG table spaces
to gain &
these benefits with containing
static Planstables
/ Packages
SYSOBJ
with
Most new function – Rebind
index page splits
variable length
unavailable  AsymmetricSYSPKAGE
 New accessStart
paths
available
with rebind columns to use RRF
& Load
of RTS
Running DB2 9 code
 More archive logging buffers
Most new function
Regression testing
 DB2 9 Utilities (except online utility support for large format input data sets &
unavailable
RECOVER to PIT with consistency)
RUNSTAT / REBIND
Catalog V9 State A
Catalog V9 State B
V9 State B
 Data sharing improvements
(except for logCatalog
contention
relief)
 Rebinding can also help to identify incompatibilities (like new reserved words)
 No new SQL features
DB2 9 for z/OS Migration Modes
 Catalog Modes Illustrated
– Convert / Revert Mode Options
– The “star” modes (CM*, ENFM*) help explain why some new
function may appear before its expected time ( like a Universal
Table Space in CM )
DB2 for z/OS
V8
Migrate
NFM
DB2 9
for z/OS
CM
DB2 9
for z/OS
ENFM
Convert
Revert
DSNTIJCS
V8 Catalog
Catalog V9 State A
DB2 9
for z/OS
NFM
Convert
Revert
DSNTIJES
DB2 9
for z/OS
CM*
DB2 9
for z/OS
ENFM*
Catalog V9 State B
Catalog V9 State B
DSNTIJCS
DB2 9
for z/OS
CM*
DSNTIJCS
V9 Modes – An Overview
CM Compatibility Mode - This is the mode DB2 is in when V9 is started for the first time from
V8. It will still be in CM when migration job DSNTIJTC has completed. No new function can be
executed in CM. Data sharing systems can have V8 and V9 members in this mode. DB2 can
only migrate to CM from V8 NFM.
ENFM Enabling New Function Mode - This mode is entered when CATENFM START is
executed (the first step of job DSNTIJEN). DB2 remains in this mode until all the enabling
functions are completed. Data sharing systems can only have V9 members in this mode.
NFM New Function Mode - This mode is entered when CATENFM COMPLETE is executed
(the only step of job DSNTIJNF). This mode indicates that all catalog changes are complete
and new function can be used.
ENFM* This is the same as ENFM but the * indicates that at one time DB2 was at NFM.
Objects that were created when the system was at NFM can still be accessed but no new
objects can be created. When the system is in ENFM* it can not fallback to V8 or coexist with
a V8 system.
CM* This is the same as CM but the * indicates that at one time DB2 was at a higher level.
Objects that were created at the higher level can still be accessed. When DB2 is in CM* it can
not fallback to V8 or coexist with a V8 system.
DB2 9 Catalog
 New Catalog Table Spaces for
–
–
–
–
–
Real-Time Statistics
New page size for SYSOBJ
XML
Trusted Context
Extended Index definitions
Catalog Table Spaces
DB2 for z/OS V8
New TS for
Real-Time Stats
TABLESPACE PAGESIZE
---------+---------+---SYSCOPY
4
SYSDBAUT
4
SYSDDF
4
SYSEBCDC
4
SYSGPAUT
4
SYSGROUP
4
SYSJAUXA
4
SYSJAUXB
4
SYSJAVA
4
SYSPKAGE
4
SYSPLAN
4
Auxiliary Table to
hold TEXT from
Routines
SYSSEQ
SYSSEQ2
SYSUSER
SYSDBASE
SYSGRTNS
SYSHIST
4
4
4
8
8
8
SYSOBJ
SYSSTR
SYSVIEWS
8
8
8
SYSSTATS
16
New page size
XML &
Trusted Context
Extended Index
Definitions
SYSALTER
32
22 Tablespaces
DB2 9 for z/OS
TABLESPACE PAGESIZE
---------+---------+--SYSCOPY
4
SYSDBAUT
4
SYSDDF
4
SYSEBCDC
4
SYSGPAUT
4
SYSGROUP
4
SYSJAUXA
4
SYSJAUXB
4
SYSJAVA
4
SYSPKAGE
4
SYSPLAN
4
SYSRTSTS
4
SYSSEQ
4
SYSSEQ2
4
SYSUSER
4
SYSDBASE
8
SYSGRTNS
8
SYSHIST
8
SYSPLUXA
8
SYSSTR
SYSVIEWS
SYSXML
SYSCONTX
SYSOBJ
SYSROLES
SYSSTATS
SYSTARG
SYSALTER
8
8
8
16
16
16
16
16
32
28 Tablespaces
DB2 9 CPU Performance
 The target for DB2 9 CPU performance is to be roughly
equivalent or marginally better relative to V8
 Mileage will vary
 Customers running DB2 9 on old hardware (z800/z900)
will likely see CPU regression - maybe 10%
 Data sharing customers running on DB2 9 (NFM) may
see significant savings from reduced LC19 contention
and less spin to get unique LRSN
Utilities Performance Improvements
– Parallelism for REORG – V9
• 10-40% elapsed time improvement
– Parallel log apply for REORG – V9
Parallelism for CHECK INDEX – V9
• Up to 30% improvement in elapsed time, 5% CPU degradation
– Utility CPU time reduction – V9
•
•
•
•
•
•
•
•
UTL
5-20% for RECOVER, REBUILD, REORG
5-30% for LOAD
20-60% for CHECK INDEX
35% for LOAD partition
15% for COPY
30-50% for RUNSTATS INDEX
40-50% for REORG INDEX
Up to 70% for LOAD REPLACE of single partition
WLM assisted buffer pool management







DB2 registers the BPOOL with WLM.
DB2 provides sizing information to WLM.
DB2 communicates to WLM each time allied agents encounter
delays due to read I/O.
DB2 periodically reports BPOOL size and random read hit
ratios to WLM.
just as though an ALTER BUFFERPOOL VPSIZE
command had been issued.
DB2 V9 restricts the total adjustment to +/- 25% the size of the
buffer pool at DB2 startup
if a buffer pool size is changed and later DB2 is shut down and
subsequently brought up, the last used buffer pool size is
remembered across DB2 restarts !!!!!!
WLM assisted buffer pool management
DBM1
ALTER BUFFERPOOL
AUTOSIZE option
WLM
Data Collection
DB2 Periodic Report
BP0
BP1
BP2
BP7
Buffer Pool Sizes
Hit Ratio for Random Reads
Bufferpool Adjustment
+ - 25%
1 Plots size and
hit ratio over
time.
2 Projects effects
of changing
the size
REORDERED ROW FORMAT
 in DB2 9 new function mode (NFM)
 REORG or LOAD REPLACE, changes the row format from
basic row format (BRF) to reordered row format (RRF)
– NO EDITPROC or VALIDPROC
 more efficient compression dictionary IF you rebuild the
dictionary AFTER converting over to reordered row format.
 REORG and LOAD jobs with KEEPDICTIONARY specified
 the introduction of APAR PK41156 that makes a change to
REORG and LOAD REPLACE so they ignore
KEEPDICTIONARY for that one time run when the rows are
reordered and allows for a rebuild of the dictionary regardless of
the KEEPDICTIONARY setting.
 APAR also introduces a new keyword APAR also introduces a
new keyword HONOR_KEEPDICTIONARY and it defaults to
NO
Reordered Row Format (RRF)
 Automatic repositioning of variable length columns to end of row
– Length attributes replaced with indicators positioned after fixed length columns
 Any table space created in DB2 9 NFM
 To Convert:
– REORG or LOAD REPLACE a table space or partition
– ADD PARTITION
– No EDITPROCs or VALIDPROCs
• EDITPROCs may need to be updated if implemented for specific columns
• Byte RFMTTYPE passed to indicate fixed length, basic, or reordered format
• Consider this impact on tables encrypted via an EDITPROC
– DSN1COPY impact during the transition period across environments
 PIT RECOVER will set the table space to the row format of the PIT
 Catalog / Directory remains in Basic Row Format (BRF)
Prefix
DSN
Fixed Length Cols
Varchar
Indicators
Varying Length Cols
Reordered Row Format (RRF)
 Logging Considerations
– Variable length rows that DO NOT change length:
• Logging is from first byte of first changed column to last byte of
last changed column
• RRF should not negatively impact logging in this case
– For variable length rows changing length & compressed
rows
• Logging is from first changed byte until the end of the row
• One consideration may be where variable length columns are
placed at the end of the row in V8 AND where the length
changes
– Now the logging will be from the indicators (offsets).
Prefix
DSN
Fixed Length Cols
Varchar
Indicators
Varying Length Cols
RRF
Varchar Performance Improvement
 Old tuning recommendation for rows with many columns
with any varchar present
F1 F2
V3
F4
F5
V6
– V9 DB2 internally executes this recommendation and more
 2 times or more improvement observed when many rows
with many varchars are scanned and/or fetched using
many predicates
 No difference if no varchar , Under 5% improvement for a
typical online transaction
 Reorg with rebuild compression dictionary if varchar
columns when migrating to V9
Access Path Stability

New function of DB2 9 (PK52523)
– Protects customers against access path regression
– Allows for a “safe” way to REBIND (fall back)
– Available even in DB2 9 (CM) as it can benefit migration and
fallback
– Strongly recommended (SPT01)
– Make sure that the pre-conditioning APAR for Plan Stability
(PK52522) is
– applied on all V8 (NFM) systems
 What is the problem?
– REBINDs can cause access path changes
– Most of the time, this improves query performance …
… But when it doesn’t
No easy way to undo the REBIND
Can lead to a lot of grief to our customers and to IBM
Access Path Stability
 Delivered with APAR PK52523 (V9)
– Preconditioning APAR PK52522 (V8 / V9)
• For fallback to V8 and coexistence with V8 / V9) – V8 toleration of multiple package
copies
• Also causes DB2 to delete old copies of PLANMGMT packages invalidated due to
database changes
 REBIND PACKAGE... PLANMGMT(OFF | BASIC | EXTENDED)
– Or REBIND TRIGGER PACKAGE
 ZParm PLANMGMT is online updateable
 Options:
– OFF (default)
• Do not use plan stability
• Package continues to have one active copy
– BASIC:
• Package has one active copy and one old (previous) copy
– EXTENDED:
• One active and two old / preserved package copies
• The preserved copies are the previous and original copies
OPT
Access Path Stability
 REBIND PACKAGE...SWITCH(PREVIOUS | ORIGINAL)
– SWITCH(PREVIOUS): toggles previous and current copies
– SWITCH(ORIGINAL): previous deleted; current->previous; original cloned to
current
 FREE PACKAGE...PLANMGMTSCOPE(ALL | INACTIVE)
– ALL is the default and frees all copies
– INACTIVE frees all old copies
 SYSPACKAGE reflects the current copy
– Other package related tables reflect dependencies of all packages
 DTYPE column of SYSPACKDEP overloaded to indicate ‘P’revious or
‘O’riginal
 To keep one V8 package
– REBIND with PLANMGMT(BASIC) once
– Subsequent REBINDs with PLANMGMT(OFF)
– REBIND SWITCH(PREVIOUS) can be used to use the original V8 package
OPT
Access Path Stability
 Before falling back to V8
– REBIND...SWITCH to the V8 package before fallback
– The V8 preconditioning maintenance will tolerate additional copies
 Restrictions
– No Native SQL Procedure support today
– No support for DBRMs bound into Plans.
 Impacts
– Requires additional SPT01 space
• Double for packages with BASIC
• Triple for those with EXTENDED
– REBIND can take 10 – 40% additional CPU
– Access Path Stability is not “sticky”. Except for the ZParm, it the
chosen level must be specified on the REBIND.
OPT
Optimization Service Center
Identify Problem Query
Tune Problem Query
Monitor & Capture Query Workload
Tune Query Workload
Converged TEMP Space
 Single source for all temporary space in DB2
– Workfile (work files and Created Global Temporary Tables)
– Temp DB (Static Scrollable Cursors and Declared Global Temporary
Tables)
– Merged into Workfile Database
– In CM & NFM
 The workfile database is the only temporary database
 Supports 4K and 32K page sizes, with automatic selection of the appropriate
page size
– Expect an increased use of the 32K temp space
– Consider sizing your 32K @ 50% - 100% of your 4K buffers
• Monitor statistics and adjust for actual usage
 Access is virtualized for small amounts of data, eliminating cost of work file
creation (reduced CPU and I/O)
– At runtime, a result fitting in 1 data page does not create a workfile
– ORDER BY and FETCH FIRST n ROWS without index support
• Uses memory replacement technique if result fits within a 32k page
• Sort is avoided
 New ZParm for preventing workfile monopolization (MAXTEMPS)
 IFCID 002 & 343 updated to report usage and exceptions
VST
Temporary Space – The DB2 V8 Picture
Installation support
(DSNTIJTM)
No installation
support
CREATE DATABASE
xxx as WORKFILE … *
WORKFILE
Define VSAM Dataset
CREATE
TABLESPACE
DSN4K01 IN xxx …
TEMP
CREATE
DATABASE xxx as
TEMP …
Declared
temporary
tables for SSC
Work files
Created global
temporary
tables
Declared global
temporary
tables
* Only in a data sharing environment – in non-data sharing syntax is CREATE DATABASE DSNDB07
Temporary Space – The DB2 9 Picture
Created
global
temporary
tables
Work files
WORKFILE
Declared
global
temporary
tables
Declared
temporary
tables for
SSC
Installation and migration support
(REXX program called by DSNTIJTM)
CREATE DATABASE xxx as WORKFILE;
DSNTWFG DB41 DB2ADM xxx +
3 10 16 BP0 SYSDEFLT +
1 20 16 BP32K SYSDEFLT
 Declared Global Temporary Tables and Static Scrollable Cursors now
use the WORKFILE database instead of the TEMP database
 Uses DB2-managed (instead of user-managed) storage in SYSDEFLT
storage group
 Segmented table space organisation (user-defined SEGSIZE or
default of 16)
 4KB and 32KB page sizes only – no 8KB or 16KB
Planning For Converged TEMP Space
 Migration from DB2 V8
– To reclaim TEMP database storage, *YOU* must drop the TEMP
database and reallocate the storage
– Recommendation: Do not drop the TEMP database until you are sure
that you will not return be falling back to V8, to avoid having to
recreate it after fallback
 New installation panel for work file database definitions (DSNTIP9)
– In migration mode, if you specify non-zero values
• Migration job DSNTIJTM will create additional DB2-managed
WORKFILE table spaces in the SYSDEFLT storage group  new
REXX program DSNTWFG
• DB2 does not take into account the existing work file table spaces
 Recommendation: set the 'DSVCI' ZPARM to YES to allow DB2 to match
VSAM CI size to table space page size
 Ensure you have 32KB WORKFILE table spaces for Declared Global
Temporary Tables and Static Scrollable Cursors
Controlling Temporary Space Utilization
 Control of temporary space utilization at the
agent level
 New ZPARM: MAXTEMPS
WORK FILE
DATABASE
– Macro DSN6SYSP, panel DSNTIP9
 If MAXTEMPS is exceeded for any given
agent:
SQLCODE = -904, ERROR:
UNSUCCESSFUL EXECUTION CAUSED BY AN
UNAVAILABLE RESOURCE.
REASON 00C90305,
TYPE OF RESOURCE 100, AND
RESOURCE NAME = 'WORKFILE DATABASE'
SQLSTATE = 57011
DB2 9 for z/OS – Addressing corporate data goals
 Improved IT Infrastructure for
Compliance Efforts
– Trusted security context
– Database roles
– Auditing, encryption improved
 Simplify development and porting
– Many SQL improvements
– Native SQL stored procedures
– Default databases and table spaces
 Data Warehousing
– Dynamic index ANDing for star schema
– EXCEPT and INTERSECT
 Decrease Complexity and Cost
–
–
–
–
–
Partition by growth
Performance improvements
Volume-based COPY/RECOVER
Index compression
Optimization Service Center
 Evolve Your Environment & SOA
– Integrated pureXML®
– WebSphere® integration
 Continuous Availability
– Schema evolution enhancements
– Fast table replacement
Native SQL Procedural Language
 Eliminates generated C code and compilation
 Fully integrated into the DB2 engine
– Any SQL procedure created without the FENCED or
EXTERNAL keywords are native SQL procedures
 zIIP enabled for DRDA clients
 Extensive support for versioning:
–
–
–
–
–
VERSION keyword on CREATE PROCEDURE
CURRENT ROUTINE VERSION special register
ALTER ADD VERSION
ALTER REPLACE VERSION
ALTER ACTIVATE VERSION
 BIND PACKAGE with new DEPLOY keyword
SQL
Past Table Spaces Options
 Past table space options
– Simple
• Multi table, interleaved
– Segmented
• Multi table, no page sharing
• Good with mass deletes
• 64GB
– Partitioned
• One table per table space
• 128TB
• Doesn’t have the internal space map like that of a segmented
table space.
DSN
Universal Table Spaces
 Universal Table Space
– Combination of segmented with partitioning options
• Better space management
• Support of mass deletes / TRUNCATE
– If partitioned
• Still must be one table per table space
• Can choose Range Based partitioning (as before: PBR)
• Can choose Partitioned By Growth (PBG)
– DROP / CREATE to migrate existing page sets
– Simple table spaces can not be created
• Default table space is now Segmented
DSN
Universal Table Spaces – Partitioned
By Growth
 Partition By Growth (PBG)
– Single-table table space, where each partition contains a
segmented page set (allows segmented to increase from
64GB to 16TB or 128 TB with 32K pages)
– Eliminates need to define partitioning key and assign key
ranges
– Partitions are added on demand
• A new partition is created when a given partition reaches DSSIZE
– See the SQL Reference for DSSIZE rules given the page size &
number of partitions
• Up to MAXPARTITIONS
– Retains benefits of Utilities and SQL parallelism
optimizations for partitioned tables
– SEGSIZE defaults to 4 & LOCKSIZE defaults to ROW
DSN
Universal
Table
Spaces
 Partition By Growth (PBG)
– CREATE TABLESPACE…. MAXPARTITIONS n
• Can specify DSSIZE
• Only the first partition is created with the CREATE statement (if DEFINE
YES)
– No USING VCAT.
– The compression dictionary is copied as new partitions
are created.
– Also syntax to specify PGB on CREATE TABLE, when
defaulting the DB & TS.
– Considerations:
•
•
•
•
•
DSN
Single-table table space
Always defines as LARGE
Need PBR for query partition elimination
No LOAD PART, ALTER ADD PART, or ROTATE PART
All indexes are NPSIs
Universal Table Spaces
 What kind of Table Space will be created?
CREATE
SEGSIZE
TABLESPACE..
.
NUMPARTS
MAXPARTITION Comments
S
*
Segmented
*
UTS PBG
*SEGSIZE is optional.
Default for explicitly
created TS & implicitly
created TS prior to
NFM.
SEGSIZE defaults to
4.
Default for NFM
implicitly created TS.
Single table TS.
*SEGSIZE is optional
& will default to 4.
UTS PBR
Single table TS
No MEMBER
CLUSTER
Partitioned
TS
Partitioning TS prior to
V9
This format needed for
MEMBER CLUSTER
DSN
Index Changes









INDEX on expression
Page sizes 8K, 16K, 32K
Improved page split
Index compression
Online REBUILD INDEX
REORG without BUILD2 – not just for DPSI
Randomized index key
Not logged index space
XML index
Index Compression
 Compression of indexes for BI workloads
– Indexes are often larger than tables in BI
 Solution provides page-level compression
– Data is compressed to 4K pages on disk
– 8K, 16K or 32K pages results in 2x, 4X or 8x disk
savings
– No compression dictionaries – compression on the
fly
Index Compression: Differences
between data and index compression
Data
Index
Level
Row
Page (1)
Comp on disk
Yes
Yes
Comp in Buffer Pool
Yes
No
Comp in Log
Yes
No
Comp Dictionary
Yes
No (2)
Average Comp Ratio
10% - 90%
25% - 75% (3)
Asymmetric Index Page Splits
Multiple Sequential Insert Patterns on an Index
Sequential inserts into the middle of an index
resulted in some pages with 50% free space prior
to V9
New algorithm dynamically accommodates a
varying pattern of inserts
IDX
Relief for Sequential Key INSERT
 New page sizes: 8K, 16K, 32K for INDEX
pages
–Fewer page splits for long keys
–More key values per page
 INSERT at the end of the key range used to
result in 50% free space in each index page
–Enhanced support dynamically adapts page split
boundary to minimize wasted space in index pages
• Index key randomization
Utilities Highlights
 Extensive support has been added to DB2 utilities for the pureXML
– CHECK, COPY, LOAD, MERGECOPY, REBUILD INDEX, RECOVER,
REORG, …
 More online utilities
– Rebuild Index SHRLEVEL CHANGE
– Reorg LOB now supports SHRLEVEL REFERENCE (space reclamation)
– Check data, LOB and repair locate … SHRLEVEL CHANGE
– Check index SHRLEVEL REFERENCE supports parallel for > 1 index
 Online REORG BUILD2 phase elimination
 Intra-REORG parallelism for UNLOAD, RELOAD, LOG phases
– Merge multiple concurrent REORGs against part of the same table
– If NPIs exist, multiple concurrent REORGs must be converted to Intra-REORG
parallelism
• Otherwise the first job will run and others will receive DSNU180I and RC 8.
 Utility TEMPLATE switching
 MODIFY Recovery enhancements (apply PK69427 to avoid COPYP for some TS)
– CLONE support
– “Retain” keyword added to improve management of copies
• LAST, LOGLIMIT, GDGLIMIT
UTL
Utilities Highlights (cont.)
 COPY utility includes SCOPE PENDING support to improve usability
 The ability to recover to any point in time with consistency
– Uncommitted changes are backed out
– Significantly reduces (eliminates?) the need to run QUIESCE which can be disruptive
to applications
 Fast log apply buffer default increased from 100MB to 500MB for RESTORE
SYSTEM
– LOGAPSTG remains @ 100MB
 Volume-based COPY/RECOVER
– FlashCopy technology used to capture entire content of disk volumes
– RECOVER modified to enable object-level recovery from volume FlashCopy
• Restore assumes that the object has not moved volumes
– Eliminates labor associated with setting up COPY jobs for each database / table space
– Full integration of tape into BACKUP/RESTORE SYSTEM utilities
UTL
Trusted
Context
&
Roles
 Establishes a trusted relationship between DB2 and an external entity
– A Server or a User ID
– Once established, a provides for specialized privileges only available via the
Trusted Context via a Role
– Remote: IP Address, Domain Name or SERVAUTH security zone attributes
– Local: Job or Task name attributes
 Role
– Database entity that groups privileges
– Can be assigned to a User ID
– ROLE AS OBJECT OWNER
• CREATE
– The Role will own the object
• BIND w/o OWNER:
– The Role will own the Plan / Package
– Outbound Auth ID translation is not in effect for remote binds
• SET CURRENT SQLID will be ignored
– Trusted Context has a Default Role
 See Admin Guide, Ch.3, “Implementing your database design”
SEC
Database ROLEs
 ROLE is a “virtual authid”
– Assigned via TRUSTED CONTEXT
– Provides additional privileges only when in a
trusted environment using existing primary
AUTHID.
 Can optionally be the OWNER of DB2 objects
Trusted Security Context
 Identifies “trusted” DDF, RRS Attach, or DSN
application servers
 Allows selected DB2 authids on connections without
passwords
 􀂾 reduces complexity of password management
 􀂾 reduces need for an all-inclusive “system authid” in
app servers
 􀂾 more visibility/auditability of which user is current
running
 􀂾 enables mixed security capabilities from a single
app server
Database ROLEs Examples
 Dynamic SQL access to DB2 tables using JDBC
or CLI, but only when running on a specific server.
 DBA can be temporarily assigned a DBA ROLE
for weekend production table admin work – no
table access at other times.
 DBA uses a ROLE for CREATE statements, so
that the ROLE owns the objects he or she
creates.
 Project librarian assigned a BIND ROLE only
when running on the production code library
server – can’t BIND from any other server.
DB2 9 for z/OS Innovation: SQL
 Numerous new SQL capabilities
 Easier application porting
 Simplified application development
DB2 SQL
z z/OS V8
common
luw Linux, Unix & Windows V8.2
z
c
o
m
m
o
n
l
u
w
Multi-row INSERT, FETCH & multi-row cursor UPDATE, Dynamic Scrollable Cursors, GET
DIAGNOSTICS, Enhanced UNICODE for SQL, join across encoding schemes, IS NOT
DISTINCT FROM, Session variables, range partitioning
Inner and Outer Joins, Table Expressions, Subqueries, GROUP BY, Complex Correlation, Global
Temporary Tables, CASE, 100+ Built-in Functions including SQL/XML, Limited Fetch, Insensitive
Scroll Cursors, UNION Everywhere, MIN/MAX Single Index, Self Referencing Updates with
Subqueries, Sort Avoidance for ORDER BY, and Row Expressions, 2M Statement Length,
GROUP BY Expression, Sequences, Scalar Fullselect, Materialized Query Tables, Common Table
Expressions, Recursive SQL, CURRENT PACKAGE PATH, VOLATILE Tables, Star Join Sparse
Index, Qualified Column names, Multiple DISTINCT clauses, ON COMMIT DROP, Transparent
ROWID Column, Call from trigger, statement isolation, FOR READ ONLY KEEP UPDATE
LOCKS, SET CURRENT SCHEMA, Client special registers, long SQL object names, SELECT
from INSERT
Updateable UNION in Views, ORDER BY/FETCH FIRST in subselects & table expressions,
GROUPING SETS, ROLLUP, CUBE, INSTEAD OF TRIGGER, EXCEPT, INTERSECT, 16 Builtin Functions, MERGE, Native SQL Procedure Language, SET CURRENT ISOLATION, BIGINT
data type, file reference variables, SELECT FROM UPDATE or DELETE, multi-site join, MDC
DB2 SQL
z z/OS V9
common
luw Linux, Unix & Windows V9
z
c
o
m
m
o
n
l
u
w
Multi-row INSERT, FETCH & multi-row cursor UPDATE, Dynamic Scrollable Cursors, GET
DIAGNOSTICS, Enhanced UNICODE for SQL, join across encoding schemes, IS NOT
DISTINCT FROM, Session variables, TRUNCATE, DECIMAL FLOAT, VARBINARY,
optimistic locking, FETCH CONTINUE, ROLE, MERGE, SELECT from MERGE
Inner and Outer Joins, Table Expressions, Subqueries, GROUP BY, Complex Correlation, Global
Temporary Tables, CASE, 100+ Built-in Functions including SQL/XML, Limited Fetch, Insensitive
Scroll Cursors, UNION Everywhere, MIN/MAX Single Index, Self Referencing Updates with
Subqueries, Sort Avoidance for ORDER BY, and Row Expressions, 2M Statement Length, GROUP
BY Expression, Sequences, Scalar Fullselect, Materialized Query Tables, Common Table
Expressions, Recursive SQL, CURRENT PACKAGE PATH, VOLATILE Tables, Star Join Sparse
Index, Qualified Column names, Multiple DISTINCT clauses, ON COMMIT DROP, Transparent
ROWID Column, Call from trigger, statement isolation, FOR READ ONLY KEEP UPDATE LOCKS,
SET CURRENT SCHEMA, Client special registers, long SQL object names, SELECT from INSERT,
UPDATE or DELETE, INSTEAD OF TRIGGER, Native SQL Procedure Language, BIGINT, file
reference variables, XML, FETCH FIRST & ORDER BY in subselect and fullselect, caseless
comparisons, INTERSECT, EXCEPT, not logged tables, range partitioning, compression
Updateable UNION in Views, GROUPING SETS, ROLLUP, CUBE, 16 Built-in Functions, SET
CURRENT ISOLATION, multi-site join, MERGE, MDC, XQuery
SQL: Productivity, DB2 family & porting
 XML
 MERGE & TRUNCATE
 SELECT FROM UPDATE,
DELETE, MERGE
 INSTEAD OF TRIGGER
 BIGINT, VARBINARY,
BINARY, DECIMAL FLOAT
 Native SQL Procedure
Language
 Nested compound
 Optimistic locking
LOB File reference variable &
FETCH CONTINUE
FETCH FIRST & ORDER BY
in subselect and fullselect
INTERSECT & EXCEPT
ROLE & trusted context
Many new built-in functions,
caseless comparisons
Index on expression
Improved DDL consistency
CURRENT SCHEMA
TRUNCATE Statement
 Allows fast delete of all rows in a given table (
segmented, partitioned or simple)
 Very useful for nightly refresh of summary tables,
warehouses, etc.
TRUNCATE TABLE TABLE-NAME
< DROP STORAGE | REUSE STORAGE>
< RESTRICT WHEN DELETE TRIGGERS |
IGNORE DELETE TRIGGERS>
< IMMEDIATE>
MERGE
 Multi-row MERGE operation, using arrays
 Targets OLTP applications like SAP
MERGE INTO account AS T
USING VALUES (:hv_id, :hv_amt) FOR 5 ROWS AS S(id,amt)
ON T.id = S.id
WHEN MATCHED THEN
UPDATE SET balance = T.balance + S.amt
WHEN NOT MATCHED THEN
INSERT (id, balance) VALUES (S.id, S.amt)
NOT ATOMIC CONTINUE ON SQLEXCEPTION
SQL Improvements –
Family Compatibility






INSTEAD OF triggers
SELECT FROM UPDATE
SELECT FROM DELETE
SELECT FROM MERGE
BIGINT, BINARY and VARBINARY data types
ORDER BY and FETCH FIRST in subselect
DDL Porting Improvements
 Automatic selection of DATABASE and TABLESPACE
when DDL omits these keywords
 Automatic CREATE of UNIQUE index for PRIMARY
KEY
 Deprecated simple table space, default to segmented
structure, partition by growth
DB2 9 for z/OS Innovation: Data
Warehousing







Dynamic index ANDing for star schema
INTERSECT, EXCEPT
Query optimization improvements
Improved query performance
Index compression
Plan stability
Optimization Service Center
SQL
SKIP LOCKED DATA
data
data
X
data
data
X
X data
data
data
 Rows with incompatible locks by other transactions are
skipped
 Clause available
– On SELECT INTO, PREPARE, searched UPDATE, searched
DELETE, UNLOAD
– Effective when CS or RS is in use
• Otherwise it is ignored
– Data is locked at the row or page
 QW0018SK – ROWS SKIPPED DUE TO INCOMPATIBLE
LOCK HELD
– Reported in IFCID 018
 Logic / Scenario
– When a transaction needs to find work to do, regardless of
order.
– Messaging applications without strict ordering requirements
expect to be able to skip over records that are locked by other
transactions
SQL
data
Intersect/Except/Union semantics
R1
R2
INTERSECT
R1
R1
R2
EXCEPT
(Difference)
R2
R1
UNION
*There are some variations and restrictions
UNION ALL
R2
Query Enhancements
 SQL enhancements: INTERSECT, EXCEPT, cultural sort,
caseless comparisons, FETCH FIRST in fullselect, OLAP
specifications: RANK, DENSE_RANK, ROW_NUMBER …
 pureXML integration and text improvements
 Index improvements: Index on expression, Index
compression, …
 Improved Optimization statistics: Histogram
 Optimization techniques
– Cross query block optimization and REOPT(AUTO)
– Generalize sparse index & in-memory data cache method
– Dynamic Index ANDing for Star Schema
 Analysis: instrumentation & Optimization Service Center
CREATE TABLE … APPEND(YES)
 New APPEND option:
–Maximizes performance for “INSERT at end”
–Avoids overhead of attempting to preserve
clustering sequence
–CREATE or ALTER table
LOB Function
 SQL
File reference variables
FETCH CONTINUE
Automatic object creation
 Utilities
–REORG reclaim fragmented space and improve
access performance
–REORG share level reference (read only)
–Online CHECK LOB & CHECK DATA
–Sample unload DSNTIAUL
LOB Performance/Scalability


LOB lock avoidance – LRSN and page latching is used
instead for consistency checks
New network flows for delivering LOBs
–JDBC, SQLJ, and CLI will let server determine
whether to flow LOB values or LOCATORs based on
size thresholds
–Significant reduction in network traffic
–Greatly reduces frequency of FREE LOCATOR
statements
DDF Improvements
 64-bit addressing by DDF
– Special “shared private” with xxxDBM1 to eliminate
many data moves on SQL operations
 Prepare for elimination of PRIVATE protocol requester
– DB2 9 did not eliminate DDF Private Protocol
– Plan is to eliminate in DB2 9+1 release
– If do not convert from Private to DRDA protocol, will
not be able to migrate to DB2 9+1 release
– DSNTP2DP (Private to DRDA Protocol Catalog
Analysis Tool) REXX program which looks at the
DB2 Catalog
Volume-based COPY/RECOVER
 FlashCopy technology used to capture entire
content of disk volumes
 RECOVER modified to enable object-level
recovery from volume FlashCopy
– Restore assumes that the object has not moved
volumes
 Eliminates labor associated with setting up COPY
jobs for each database / table space
 Full integration of tape into BACKUP/RESTORE
SYSTEM utilities
DB2 9 Vstor Constraint Relief
 DDF address space runs in 64-bit addressing mode
– Shared 64-bit memory object avoids xmem moves between DBM1
and DDF and improves performance
– Constraint relief
 DBM1, the following are moved above the bar in V9
–
–
-
Parse trees
EDM fixed pools
SKPTs / SKCTs (primarily static SQL). Also part of CTs/PTs
Pageset blocks, RTS blocks
Local SQL statement cache
Some thread-related storage
 For installations that are constrained on DBM1 vstor:
– 200 to 300MB or more of savings expected
– Mainly from EDM related storage (static SQL) and dynamic statement
cache (dynamic SQL)
DBM1 Virtual Storage below 2GB
DB2 9 for z/OS Innovation: SOA
and XML
 Integration with WebSphere
 Native XML data type, hybrid
data base server
Optimistic Locking Support
 Built-in timestamp for each row or page
– Automatically updated by DB2
– Allows simple timestamp predicate to validate that row
has not changed since last access
 Eliminates need for complex predicates on
WebSphere CMP updates, improves performance
API Support
 XML type is supported in
– Java (JDBC, SQLJ), ODBC,
– C/C++, COBOL, PL/I, Assembly
– .NET
 Applications use:
– XML as CLOB(n)
– XML as DBCLOB(n)
– XML as BLOB(n)
– All character or binary string types are
supported
 XMLParse and XMLSerialize apply (implicitly or
explicitly)
When To Use XML?
 Sparsely populated data
 Frequent DDL changes
 Short term complex data
 Complex snapshot data
 Relatively static data that is not frequently updated
 Data which is not frequently referenced on WHERE
predicates and not frequently updated
Tedious normalization and frustrated changes of
schema are an indicator for using native XML.
Example1: Auto Insurance Policy Variations
 Each vehicle has many different features, and insured may
choose different policy variations
 New features may come up each model year, and new
policy variations can come up too.
 It’s hard to design a set of columns to cover all possible
features and variations
 Some of the features and variations need to be searched
upon
 Solution: use XML column
Example2: Customer Statements






Customer statements get generated in XML format
XML file is used to print/mail to customer
XML documents are tagged with keywords
XML document can be stored natively in DB2
Keywords are searched to respond to customer inquiries
Able to easily recreate the original document sent to
customers (no transformations needed)
 Instead of side table and CLOB, use XML and indexing on
the tagged keywords
 Benefit: flexible, high performance
DB2 9 – Summary of pureXML Support







XML as a native data type
Pure XML storage and indexing
SQL/XML and XPath support
Integration with traditional relational data
XML Schema Repository
Schema validation
Application Support (Java, C/C++, .NET,
PHP, COBOL, PL/1 etc.)
 Visual Tooling, Control Center
Enhancements
 DB2 Utilities: Load, Unload, Reorg, etc.
 …and more
DB2 9
Secure and
Resilient
Infrastructure
for a New
Breed of Agile
Applications
DB2 9 for z/OS Innovation:
Continuous Availability
 Online schema evolution
 More online utilities
 Data sharing enhancements
Schema Evolution – Database Definition
On Demand









Fast replacement of one table with another
Rename column and index
Rename SCHEMA and VCAT
Table space that can add partitions, for growth
Improve ability to rebuild an index online
Online reorganization with no BUILD2 phase
Modify early code without requiring an IPL
Alter table space and index logging
Create & alter STOGROUP SMS constructs
CLONE Tables
 Allows fast replacing production data without
renames and rebinds
– A capability to support online load replace
 ALTER TABLE to create a Clone Table
– All indexes are also cloned
– Table and Index data are not copied
– Base and Clone tables share the same table
space and index names
– Underlying data sets are differentiated by a
data set instance number
CLONE Tables…
 A clone table can only be created
– On a single table in a table space (partitioned or
non-partitioned)
– No RI or Trigger on the base table
 Use insert or load to populate clone tables
 Utilities (except RUNSTATS) can operate on
clone tables with a new CLONE keyword
Partition by Growth
 New partitioning scheme:
– Single table tablespace, where each partition
contains a segmented pageset (allows segmented
to increase from 64GB to 16TB or 128 TB with
32K pages)
–Eliminates need to define partitioning key and
assign key ranges
–A new partition is created when a given partition
reaches DSSIZE (defaults to 64G)
–Retains benefits of Utilities and SQL parallelism
optimizations for partitioned tables
DB2 9 Utilities
 Support for all new functions in DB2 Version 9 for z/OS
product (universal table spaces, XML, not logged, etc.)
 More online utilities
– Rebuild Index SHRLEVEL CHANGE
• Great for building new non-unique indexes
– Reorg enhancements
• Reorg LOB now supports SHRLEVEL REFERENCE
• LOB space reclamation
• Partition-level capabilities (not available with REBALANCE)
– Partition parallelism (UNLOAD/RELOAD) in a single utility statement
– Elimination of the BUILD2 phase outage
 Recover to consistent PIT without need for a quiesce
DB2 9 Utilities
 More online utilities
– Check data, LOB and repair locate … SHRLEVEL CHANGE
– Check index SHRLEVEL REFERENCE supports parallel for > 1 index
– Load replace (shrlevel change) with CLONE TABLE function
 Always perform CHECKPAGE on the COPY utility
– Prior to V9, CHECKPAGE was optional, with about ~5% CPU
overhead, and if a broken page was encountered (DSNU441I for
space maps or DSNU518I for others, both RC8), then copy-pending
was set
– Now, COPY always performs these checks (with reduced overall
CPU!) and no longer sets copy-pending, so…. Check those RCs!
– A new SYSCOPY record type is written if a broken page is detected to
force a full image next since dirty bits may have already been flipped
off in the space map pages