Sunday, February 26, 2006

DB2 UDB for z/OS Version 8 Performance Topics

Now that many sites are migrating to DB2 V8 performance topics related to this new version are gaining popularity. Although there have been a large number of improvements made to DB2 in terms of scalability, application porting, security, and continuous availability, there are also some things you'll need to prepare your systems for.

Luckily, IBM has just updated its very useful redbook titled DB2 UDB for z/OS Version 8 Performance Topics (SG24-6465). This redbook was initially published in April 2005, but was updated with new V8 performance information and details in late February 2006. So, if you haven't picked this title up yet, now would be a good time to download and peruse it. And if you have already reviewed it, you might want to download the updated version.

The redbook gives guidance on SQL performance, subsystem performance, availability and capacity enhancements, utility performance, networking improvements, data sharing enhancements, installation and migration information, and coverage of IBM's performance tools for DB2.

If you have already migrated to V8, or are planning a migration soon, then DB2 UDB for z/OS Version 8 Performance Topics should definitely be on your reading list.

Monday, February 20, 2006

Can You Write a Redbook?

If you've been working with mainframes for any period of time you have almost certainly become familiar with the IBM redbook. These are supplemental manuals that IBM writes and distributes free-of-charge. They can be on just about any technical topic.

Well, when I said IBM writes them, I should have been more clear. IBM guides the writing of them and solicits its customers to help out. It does this via residencies. A residency is an intensive, multi-week work effort where small teams explore and document product implementation, integration and operations. Each team is directed by an IBMer from their technical publications group. The team will consist of professionals from IBM field and development, from IBM Business Partners, from customers, and from the marketplace in general. So, you too, can research and write an IBM redbook!

Of course, you have to make sure that you have the expertise, willingness, and time to work on the project.

For a list of available residencies, click here:

And if you are a DB2 for z/OS practitioner (as most readers of this blog should be) there is a very interesting residency available Powering SOA with DB2 for z/OS.
The redbook is going to depict how DB2 is SOA-enabled to provide web services. Topics to be covered will include:
  • the Service Oriented Architecture,
  • DB2 z/OS Web Services support,
  • Web Services operations,
  • Security, Provider and Consumer scenarios,
  • SOA runtime environments to access DB2 for z/OS,
  • Service Data Objects, and
  • XML functions.
So, if you know any of this, are interested in learning how to develop web services for DB2 for z/OS, and have always wanted to help write one of those redbooks, click below and read how to participate:

Wednesday, February 15, 2006

VSAM Demystified

VSAM is used "under the covers" of every DB2 page set. VSAM is also used as the storage mechanism by some IMS databases. It is also used to store a lot of mainframe data outside the control of any DBMS. But there is a lot of confusion about what exactly VSAM is, how it can be used, and how it differs from a DBMS.

I wrote an article for IDUG Solutions Journal titled On VSAM and DB2 that offers some high-level details on the differences between the two. But if you are looking for a great, in-depth publication on VSAM there is a great redbook you should check out with the same name as this blog entry: VSAM Demystified.

This book is intended to be used as an initial point of reference for VSAM functions. It is sure a lot easier starting here than wading through the many IBM manuals on the subject. And it is less costly than some of the great books on VSAM out there. (For those those interested in some good VSAM books for further research consider these: VSAM Access Method Services by James Martin, VSAM by Doug Lowe, and VSAM for the COBOL Programmer also by Doug Lowe).

Anyway, back to the IBM redbook: this book helps to demystify VSAM and gives you the information necessary to understand, evaluate, and use VSAM properly. It covers VSAM basics, performance issues, assists with VSAM problem determination, VSAM recovery, gives guidance on managing VSAM data sets, and even discusses issues like VSAM Record Level Sharing and DFSMStvs.

If you are looking for a concise, useful, and cost-effective resource to bolster your VSAM knowledge, you should download and read VSAM Demystified today!

Friday, February 10, 2006

Evaluating DB2 Tool Vendors

Although the most important aspect of DB2 tool selection is functionality and the way it satisfies your organization’s needs, the nature and stability of the vendor that provides the product is also important. So, of course, you will need to be sure that the tool you are evaluating meets your functional specifications.

And in this day and age you should really do the investigative work required to find out the real level of support for DB2 V8 that is in the GA version of the tool. Most vendors have implemented V8 in stages, so be sure the features you plan to use first are supported within the tool.

Moreover, you should also investigate the vendor offering the tool (or tools) under consideration. Keep in mind that older does not always mean better -- and newer does not always mean more innovative. It depends (doesn't it always). You need to investigate the vendors thoroughly and the following list of questions can help:

1. How long has the vendor been in business?

2. How long has the vendor been supplying DB2 tools?

3. Does your company have other tools from this vendor? How satisfied are the users of those tools?

4. Are other organizations satisfied with the tool you are selecting? Obtain a list of other organizations that use the same tool and contact several of them.

5. Does the vendor provide a 24-hour support number? If not, what are its hours of operation?

6. Does the vendor have a toll-free number? If not, how far away is the company from your site? You want to avoid accumulating long-distance charges when you are requesting customer support from a vendor.

7. Does the vendor provide Web support? The Web support should be in addition to phone support, not a replacement.

8. Evaluate the response of the technical support number. Call the number with technical questions at least four times throughout the day: before 8 a.m., around noon, just before 5 p.m., and again after 9 p.m. These are the times when you could find problems with the level of support provided by the vendor. Was the phone busy? Were you put on hold? If so, for how long? When you got a response, was it accurate and friendly? Did the person who answered the phone have enough technical knowledge to be useful?

9. How knowledgeable are the technical support representatives who answer your test calls? Do they know their products inside and out, or do they struggle? Do they know DB2 well (such as a former DBA) or are they unseasoned?

10. Will the vendor answer DB2 questions free of charge in addition to questions about its product? Sometimes vendors will, but they don’t advertise the fact. Try it out by calling the technical support number.

11. Does the vendor provide a newsletter? How technical is it? Does it provide information on DB2 and the vendor's tools or just on the vendor's tools? Is it printed and mailed, e-mailed, or available over the web?

12. Does this vendor supply other DB2 tools your organization might need later? If so, are they functionally integrated with this one? Does the vendor supply a full suite of DB2 products or just a few?

13. Does the vendor integrate its tools with other tools? For example, can a product that analyzes databases to determine whether a REORG is required integrate with your shop's job scheduler?

14. Does the vendor provide training? Is it onsite training? DB2 training and product training?

15. Are installation, technical, and user manuals provided free of charge? Are the manuals available in both hard and soft copy? Will the vendor deliver additional documentation or error-resolution information by overnight mail? e-mail? fax?

16. How are software fixes provided? Electronically? By tape? On the Web? Is a complete reinstallation required? Are fixes typically accomplished using zaps? Does the vendor support SMP/E?

17. How many man hours, on a short notice, is the vendor willing to spend to solve problems? Is there a guaranteed time limit?

18. Is the vendor willing to send a representative to your site to do a tailored product presentation? How knowledgeable is the rep?

19. Is the vendor an IBM business partner? How soon will the vendor's tools be modified to support new DB2 releases and versions? Does the vendor participate in IBM's Early Ship Program (ESP) for new DB2 versions and releases?

20. Have the vendor's tools been recently reviewed or highlighted in industry publications? If so, read the articles.

21. Have the vendor's tools been assessed by industry analyst groups (e.g. Gartner, Forrester, etc.)? If so, read the reviews.

22. Will the vendor assist in developing a cost justification? Most tool vendors are more than willing to provide cost justification to help you sell upper management on the need for the tool.

23. Does the vendor provide sample JCL to run its product? Can any needed JCL be automatically generated by the product? Are templates provided to tweak the JCL to your shop standards?

24. Does the vendor charge an upgrade fee when the processor is upgraded? How flexible are the contract terms and conditions? Do they offer usage-based licensing? Other terms?

26. What guarantees are available from the vendor against it being sold or going out of business? Will the vendor supply the source code for the tool, or perhaps offer a money-back guarantee?

27. Is the vendor willing to set a ceiling for increases in annual maintenance charges?

28. Does the vendor supply DBA tools for other DBMSes used at your shop? Can the same tool, using the same interface, be used to manage multiple databases across multiple operating systems?

29. How does the vendor rank enhancement requests?

30. What is the status of the vendor? Have recent business down turns resulted in lower market share? If so, what is the company doing to regain its position?

31. Did the company recently undergo a layoff? What is the retention rate of their development and support staff?

32. Are there any outstanding lawsuits? Have recent events resulted in downsizing? What are their plans to reverse this trend?

Use these questions to provide a basis for evaluating DB2 tool vendors. You can judge for yourself which criteria are most important to your organization.