DB2 V8 –
What To Do Before The Product Is Even Ordered
By
John Speredelozzi, Speredelozzi Software, Inc., Sept 2004
There is more to the DB2 V8 migration then just installing and migrating the DB2 component. There are many ancillary processes that will need review, and possibly enhancement or change.
Not to worry all of you
Technical Terabyte Tweakers. All is well. Copious documentation is readily available. You
just have to find it all, digest it, identify all contingencies, and then migrate. Nothing
to it!
As most of you are already
aware, the V8 migration is a three-phase process. Phase One is the installation and
migration into Compatibility Mode. Phase Two is the move to Enabling-New-Function Mode.
And Phase Three is the New Function Mode.
If you have not done so, you read in-depth a minimum
number of documents. The first document to quickly review is the DB2 UDB for z/OS Version 8
Technical Preview IBM Redbook. This will introduce you to the general architecture
and commands in Version 8.
The next is book to devour in full is DB2 UDB for z/OS Version 8:
Everything You Ever Wanted to Know, ... and More IBM Redbook. This book will give
you very detailed information on the architecture and commands.
The next document is the IBM DB2 V8
Installation Guide. This manual contains the general product and user applications
installation/migration tasks. This manual forms the basis for the DB2 product migration
sections of the Migration Support Kit (click here to go
to read our earlier newsletter article on Migration Support Kits.)
With these documents and support tools, you should be
ready to tackle the actual install and migration steps and work your way through the DB2
V8 Compatibility Mode, Enabling New Function Mode, and New Function Mode levels of
migration.
For pre-migration projects you should start
doing some housekeeping on your system and preparing yourself for all of the new gizmos
and gadgets in V8. If you have been shielded from the web world, some of the new function
might seem a little alien. Like the UNICODE implementation of the DB2 catalog.
To get a good in-depth look at the whole
UNICODE implementation, read the new DB2 UDB for z/OS
Version 8 Internationalization Guide which will tell you everything there is know
about UNICODE in DB2.
Remember that DB2 V8 requires
a minimum level of z/OS V1.3. To use some of the new features, such as the Backup System
utility or row granularity multilevel security you would have to come forward to z/OS
V1.5.
UNICODE Conversion Services is
bundled with z/OS and must be enabled. Then use the information you gleaned in the DB2
UDB for z/OS Version 8 Internationalization Guide reading assignment and check
informational APARs II13048, II13049, and II13277 for specific coded character sets use
will or intend to use. Identify the CCSIDs to be used.
Do a clean-up project on your
DB2 catalog. You might want to run some or all of the SQL queries in DSNTESQ member of
DSNSAMP lib. Or you might want validate you have no unsupported objects. YOU can use the
DSNTIJPM job to assist in identifying objects that will be unsupported in V8.
Make sure you have
EXPLAIN(YES) so that access paths don’t go way off track when you REBIND at V8. Or
you might want to purchase and use a product like ImpactManager for DB2 z/OS which will
guarantee that only REBINDs that meet or improve current performance are executed.
With the V8 introduction of
long names to the catalog, many of the tables and indexes will require the use of 8KB,
16KB, and 32KB buffer pools. So go ahead in your V7 system and allocate some minimum size
for these. Also ensure that no application objects are using these pools. Move any
application object somewhere else into an alternate pool.
Identify any applications that
will take advantage of new DB2 functions. These will require NEWFUN(YES) as part of the
pre-compile . Layout an exploitation schedule for the new features such as BACKUP SYSTEM
utility, online schema evolution, and >32K SQL statements as examples. Don’t
attempt to implement all new features at once. Build a schedule and give yourself a safe
and sane plan for the implementations.
Remember that DB2 V8 only
works with WLM Stored Procedures for any of them that have drop/create required. Existing
DB2-managed stored procedures will be OK until such time as a change to them requires a
drop/create. Then they must move to WLM-managed. So ensure the change control process for
stored procedures takes into account the WLM requirement. You might want to just go ahead
and convert all of the DB2-managed stored procedures and be done with it.
Many third party products participated at the beta test program and early ship of DB2 V8.
Beware as some products will support the DB2 V8 architecture (64-bit, UNICODE, etc) but will not tolerate any or only some of the new V8 features. A review of each vendor’s current V8 support is required and appropriate service or new version/release installation must be done. If are using the DB2 V8 MSK some of the legwork is already done and the vendor product is already identified as to if service only or a new release installation is required.
Someone in your organization is more than likely to ask you “how long” to move to Phase Two in wall clock hours of execution time.
There are several ways to estimate the execution time for the Enabling-New-Function-Mode jobs. A REORG of the eighteen catalog and directory tablespaces that ENFM will affect is the simplest way. There are some issues like do you have a maintenance window long enough to do this REORG, or tablespaces with links, or should I use V8 CM Online REORG instead of V7’s? You might create a sandbox approximation of your production catalog (not data please).
Let’s edict that while the V8 migration is underway, there will be no disaster. Tongue in cheek, chances of a disaster situation occurring during the migration are slim but hey. I live in Florida and we just had our fourth hurricane of the season strike the state. I can personally attest to the fact that on at least three of these four occasions (in the last six weeks) disaster recovery sites did go live.
The real decisions are how will you handle the CM, ENFM, and NF modes with your disaster recovery site? Should a corresponding ENFM be run (and when) to keep the production and backup sites in sync? Do we just bite the bullet and execute the ENFM or FM executions as part of attempting to bring up the backup site?
Make sure the V8 objects are updated in your backup and recovery procedures.
Since VS COBOL II is no longer supported in V8 in a z/OS 1.3 or higher system, you might want to coordinate the move to IBM COBOL (Enterprise level V2.2, V3.2 or V3.2).
Be aware that you can still run the VS COBOL II load module under LE and just hope you don’t need to recompile them.
PLI falls into this also.
There are many small projects that can and should be started and completed long before the organization orders DB2 V8. So why wait? If you are already at DB2 V7 get moving on these ancillary projects.
There are two excellent articles in z/Journal April/May 2004 edition on aspects of the pre-migration activities to be considered.
These articles are:
DB2 UDB for z/OS Version 8 - Pre-planning Your Migration by Lyon Lockwood, and
DB2 V8 z/OS Stored Procedures and Workload Manager: Realizing the Synergy and Planning For Migration by Susan Lawson and Dan Luksetich.
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