Additional DB2 10 Resources

DB2 10 is the most significant release IBM has shipped and this is reflected in its rapid adoption rate. Based on the number of customers I hear from who have either upgraded or say they're in the process of migrating to DB2 10, I can't think of another release that's been so quickly embraced. If you're ready to make the upgrade, you should know that IBM offers DB2 10 for z/OS migration planning workshops. Contact your local IBM team if you're interested in this type of training.

If there isn't a workshop in your area (or even if there is), check out the free IBM e-book, "DB2 10 for z/OS: The Smarter, Faster Way to Upgrade to DB2 10."

The first section of the e-book is authored by IBM distinguished engineer John Campbell, who takes you through planning for the upgrade. The second section is authored by IBM gold consultant Cristian Molaro, who highlights the potential cost savings that can be gained through upgrading to DB2 10.

If you've read this document, please register your thoughts in Comments.

 

DB2 9 End of Service Announcement

I recently took note of IBM's announcement to end marketing of DB2 9. Well, the DB2 9 end of service announcement quickly followed.

DB2 9 end of service is scheduled for June 27, 2014, so IBM is giving you ample time to plan your upgrade. DB2 8 end of service, however, is only a few months away. If you've already made the decision and started migrating to DB2 9, you probably won't switch gears now (and shouldn't need to). If you haven't started planning to get off of DB2 8 though, your next move should be to DB2 10.

Granted, many companies use unsupported versions of DB2 and other IBM solutions, but there are important benefits to keeping your software reasonably current. For instance, check out this article by David Stephens. Relatedly, here's a good piece by Julian Stuhler on how to justify upgrading to IBM DB2 10 for z/OS.

So does this announcement alter your migration plans? Please post a comment and let us know.

Updates to Redbooks on DB2 10 for z/OS

I've written quite a bit about both IBM DB2 for z/OS manuals and IBM DB2 Redbooks. I generally use the manuals to educate myself about DB2 for z/OS features. When I'm looking for more in-depth details on different areas of practice within DB2, I often turn to Redbooks.

As with manuals, Redbooks are updated on a regular basis. Here's a quick list of DB2 Redbooks that I've read and used. All have been published or updated within the past year. The first two listings include links to previous blog entries I've written about these publications.

• "DB2 10 for z/OS: Configuring SSL for Secure Client-Server Communications" (published: Oct. 11, 2011; last update: Dec. 5, 2011; previous post: Getting Started with SSL)
• "Security Functions of IBM DB2 10 for z/OS" (published: Sept. 2, 2011; last update: Sept. 14, 2011; previous post: Roles and Trusted Context)
• "DB2 10 for z/OS Performance Topics" (published: June 21, 2011; last update: Dec. 6, 2011)
• "DB2 10 for z/OS Technical Overview" (published: Dec. 30, 2010; last update: Dec. 6, 2011)
• "Managing IBM DB2 10 for z/OS Using the IBM DB2 Administration Tool for z/OS Version 10" (published: April 22, 2011)
• "Extremely pureXML in DB2 10 for z/OS" (published: Jan. 28, 2011)

New Manual Covers DB2 10 for z/OS Security

Every few months, I visit IBM's DB2 product library and refresh all of my PDF manuals.

IBM was busy during the latter part of 2011. The majority of manuals have been updated since September, meaning I refreshed almost my entire DB2 10 manual library. Even if you're still on DB2 9 or DB2 8, you should check your own list, because these manuals have been refreshed as well.

In the course of my library upkeeping, I also found a new manual that you should be aware of: "DB2 10 for z/OS: Managing Security."

Since I haven't yet read this manual, I'll give you the roughest of outlines by citing some chapter titles:

Chapter 2. Managing access through authorization IDs and roles

Chapter 3. Managing access though RACF

Chapter 4. Managing access through row permissions and column masks

Chapter 5. Managing access through trusted context

Chapter 6. Managing access through data definition control

Chapter 7. Managing access through exit routines

Chapter 8. Protecting data through encryption and RACF

Chapter 9. Auditing access to DB2

 With the obvious interest customers have security and compliance issues, and given the many security-related enhancements in DB2 10, it's easy to understand why IBM came out with this new document. Diving into this information is one of my top priorities for the early new year. I'm really looking forward to reading this manual and learning more about DB2 10 for z/OS security.

My Favorite DB2 Blogs

Most of the top DB2 experts have their own blogs. These blogs can help you keep up on what’s happening with DB2 and the DB2 community. Do you have a favorite DB2 for z/OS blog? Well, if you're reading this, then I would hope I make it into your top blogger list -- and there is a healthy list of excellent DB2 blogs out there:

Planet DB2 (DB2 Blog Aggregator)

Getting the Most out of DB2 for z/OS (Willie Favero)

DB2 Portal (Craig Mullins)

DB2 USA

Native XML Database (Matthias Nicola)

DB2 News & Tips (Fred Sobotka)

Dave Beulke

DBI Blogs

IT, Life, DB2, pureXML, House Construction (Henrik Loeser)

Channel DB2

Robert Catterrall

SAP on DB2 for z/OS (Omer Brandeis)

Thoughts on DB2 (Triton)

Just DB2 Chatter (Jan Koblenzer)

DB2 Performance (Sameer Kumar)

Smart Questions

Juice DB (Rav Ahuja)

Database Diary (Conor O’Mahony)

The Fillmore Group Blog (Kim May & Frank Fillmore)

DB2 Express-C Team

Free DB2

MHC Inc (Martin Hubel)

DB2utor (Troy Coleman)

If I had to pick a favorite from this lengthy list, I'd go with Planet DB2, because it offers the deepest and most frequently updated list of active DB2 blogs.

And, honestly, DB2utor is another of my favorite blogs. One thing I like about this blog is its search capability. I've spent many hours researching and testing features. Some of these features I use only occasionally in the real world, so I can't always immediately recall every command I should issue or every function I should perform. Fortunately, when that happens, I can just search on the blog name (DB2utor) and a database term (locking) and quickly retrieve what I'm looking for -- e.g., "DB2utor locking."

 Anyway, if you didn't find your favorite DB2 blog on this list, please let me know in Comments.

 Thanks so much for reading this blog. See you in 2012.

 

Proud, Honored and Grateful

The IBM Champion program recognizes non-IBMers who make exceptional contributions to the technical community. An IBM Champion is a developer or IT professional who leads and mentors his or her peers and motivates them toward IBM solutions and services. Champions can be found running user groups, managing websites, speaking at conferences, answering questions in online forums, and writing blogs, how-to articles, and technical books. The IBM Champion program recognizes and thanks these innovative thought leaders, amplifying their voice and increasing their sphere of influence in the technical community.

I recently received the prestigious award of IBM Champion of Information Management for 2011. I'm proud and honored, and I'm grateful to the reader who submitted my name for nomination.

Learn more about the IBM Champion program -- or to make your own nomination.

Controlling System Checkpoints

Recently I was asked about controlling the number of system checkpoints being taken by DB2. In this case the DBA would see system checkpoints taken every couple of minutes, and the logs fill up as a result.

The system parameters used to control system logging are defined during the install and can later be changed in the DSNZPARMs. In older DB2 versions, the LOGLOAD paramenter controlled the number of log records written. If you set this parameter to 100,000, DB2 would take a system checkpoint once 100,000 records had been written. (DB2 will pause activity and take a system checkpoint to establish a point of consistency.) The problem with setting system checkpoints to occur with every X number of records is that you never know when a checkpoint is coming or how busy the system will be when it does. Depending on system activity, a checkpoint could come every hour -- or every second.

With DB2 8, IBM made it easier to control and consistently predict when and how frequently system checkpoints would occur. CHKTYPE, CHKMIN and CHKFREQ replaced LOGLOAD as the key parameters.

The CHKTYPE (checkpoint type) subsystem parameter indicates whether the interval between log checkpoints is to be based on the number of written log records, the time between checkpoints, or both. The acceptable values are LOGRECS, MINUTES and BOTH. The default is MINUTES, which is what I like to use. For details, see checkpoint parameters in panel DSNTIPL1 in the DB210 Installation and Migration Guide.

The parameter you choose to control the frequency of checkpoints (CHKFREQ or CHKMINS) is determined by the checkpoint type you use, LOGRECS or MINUTES. With LOGRECS, the valid values are between 1,000 and 16,000,000. With MINUTES, the valid values are between 1 and 60.

When choosing a checkpoint frequency value, you must consider the trade-offs between the overhead needed for frequent subsystem checkpoints and the time needed to restart a DB2 subsystem after a termination without a quiesce. In a production environment, you should set the frequency between 2 and 5 minutes. In a testing or development environment, a frequency between 15 and 20 minutes is acceptable.

Next week I'll discuss how log size can impact system checkpoint.

Do you tune system checkpoints? What settings do you employ for production and development? Please post your thoughts in Comments.

Keeping up with Storage Technology

While I was at SHARE a few weeks ago, I listened to IBM discuss BIG DATA and the evolution of data storage from terabytes to petabytes to exatabytes to zetabytes. As I thought about supporting these unimaginably huge numbers, I wondered further about the enhancements to storage technology and how DB2 for z/OS benefits from these changes.

Click the following link to download "Bytes Table:"  Download Bytes Table

DB2 for z/OS uses features in the Data Facility Storage Management Subsystem (DFSMS) to take advantage of improvements in both software and hardware interfaces. One area of improvement is in the size of volumes supported. The largest traditional 3390 device, 3390-54, supports 65,520 cylinders or approximately 54 GB. z/OS V1R10 introduced Extended Address Volumes (EAV), which raised the volume size to 262,668 cylinders, or 223 GB.

To give you an idea of the progression in size by device:

3390-3      Max cyls:     3,339        3GB
3390-9      Max cyls:   10,017         9GB
3390-27    Max cyls:   32,760      27GB
3390-54    Max cyls:   65,520      54GB
3390-A     Max cyls:   262,668    225TB

As you can imagine, having more datasets on one volume can increase the I/O queue time. Old-time DBAs spent many hours determining the best dataset placement and separation across I/O controllers to avoid I/O bottlenecks. Now this issue is addressed by configuring an EAV device to use parallel access volumes (PAVs). PAVs bring a significant performance improvement over traditional I/O processing by allowing a single device from a single host to process multiple concurrent requests. When you PAV-enable a logical volume, you assign a static number of PAVs to that volume. However, you may find that you can't assign enough PAVs to keep up with the workload for a given volume. To address this issue, the DS8000 series disk subsystem offers an enhanced PAV with support for HyperPAV, which provides equal or better I/O performance while using the same or fewer operating system resources.

I’m sure your storage administrator can explain it in more detail than I just did. Storage has and will continue to be enhanced in many ways that make a DBA's job easier. Take the time to learn about these new technologies. And if the latest storage technologies are already in use at your company, please share a bit about your experiences in Comments.

Preview Runstats Profile

Numerous options can be used when running a runstats utility. But one thing that customers have long asked for -- the capability to interrogate the current statistics to deterimine which parameters were used the previous time runstats was executed -- hasn't been an option. That is, until now, because IBM has developed a solution.

As of DB2 10 for z/OS, the runstats utility can store the parameters it uses for a given schema and table. Runstats can also now be used to determine when the profile was created and the last time it was used.

The profile information is stored in table SYSIBM.SYSTABLES_PROFILES. You can query the table directly to see the profiles that have been generated, or you can run runstats with the PREVIEW option. In preview mode, the gathering of new statistics is bypassed and the profile information is written out to SYSPRINT DD.

To give you an example of how this works, I excuted runstats using this parameter:

RUNSTATS TABLESPACE (COLTR05D.COLTR051)
         TABLE (COLTR05.ADDRESS_TABLE) 
         COLUMN (CITY,STATE)           
         INDEX (ALL)                   
         SHRLEVEL REFERENCE UPDATE ALL 
         SET PROFILE                   

To preview the information I just generated, I used these parameters:

OPTIONS PREVIEW
RUNSTATS TABLESPACE (COLTR05D.COLTR051)
         TABLE (COLTR05.ADDRESS_TABLE) 
         COLUMN (CITY,STATE)           
         INDEX (ALL)                   
         SHRLEVEL REFERENCE UPDATE ALL 
         SET PROFILE                   

In the following PDF you'll find the SYSPRINT DD output (Figure 1) and sample query output (Figure 2): Download Mfblog_coleman031511_figure1 and 2

I think it would have been nice if IBM made SET PROFILE a default to ensure you can view which parameters used for the runstats are available. However, it's up to you to ensure production JCL is changed to include the SET PROFILE parameter.

zNextGen Free Mainframe Education

Last week I wrote about SHARE and mentioned the zNextGen (zNG) project, which provides a networking vehicle for young mainframe professionals.

Attending SHARE conferences isn't a requirement for membership. To become an zNG member, register here.

zNG members receive access to the free mainframe online courses at Interskill.

•    To receive a new user ID/password, e-mail znextgen@interskill.com and mention your zNG membership. Once confirmed, your user name and password will be sent to you.
•   Go here to log in and start your 12 free courses
•    Contact Darren Surch (dsurch@interskill.com) if you have an expired user ID/password.

zNextGen Curriculum            
o    Assembler Introduction  
o    COBOL Programming: Basics  
o    Introduction to the CICS Transaction Server  
o    Introduction to the IBM Enterprise Environment  
o    Introduction to the REXX Programming Language  
o    JCL (z/OS): Introduction to z/OS JCL 1.11  
o    SDSF Concepts and Facilities  
o    Unicenter CA-OPS/MVS II: Event Automation Concepts and Components  
o    Using Online System Facilities: TSO/ISPF 1.11  
o    VSAM Utilities  
o    z/OS Architecture 1.11  
o    z/OS Concepts and Components 1.11