Using File Reference Variables

DB2 10 for z/OS introduced support for reading and writing LOB and/or XML data to files using file reference variables. File reference variables allow large LOB or XML values to be inserted from or selected into files rather than host variables. This saves memory because applications aren't holding large XML or LOB values.

A related benefit of using file reference variables is that you avoid storing large XML/LOB values in host application working storage. The data bypasses the application storage and travels directly to the client file system and database server.  And by keeping the data out of the application storage, you avoid any limitations the application host language may place on working storage sizes. These languages supports file reference variables: C, C++, COBOL, PL/I, Assembler, REXX and Java. 

Do you have an application that takes advantage of DB2 10 for z/OS file reference variables? Please take a moment and post a comment about your experience.

Are DBAs Still Needed?

Since IBM unveiled its big data strategy, there's been an interesting response. Some have focused on the role of the DBA, wondering if advancements like IBM Data Analytics Accelerator for z/OS (IDAA) and Netezza, which are designed to eliminate concerns over index design when storing data, make DBAs obsolete.

IBM's Susan Visser went so far as to organize a "tweetchat" on this topic: "Is the role of the DBA dead?"

As Susan notes, the debate was informative, but ultimately, it wasn't much of a debate. That's because everyone agreed that DBAs are still absolutely needed. While I wasn't able to participate in the Twitter debate myself, here's my take: We still need DBAs to understand the target system and the best physical design for the given system. Sure, since Netezza doesn't use indexes, you don’t need to worry about what index to create on the table. However, you still need to understand the physical design techniques for the Netezza system.

For more on the enduring importance of DBAs, see this post by Bjarne Nelson.

Have you tackled a performance problem on the Netezza system? If you're a DBA with experience on Netezza, I'd like to hear from you in comments.

DB2 11 for z/OS: What's ahead

IBM announced the DB2 11 for z/OS Early Support Program last fall, and a select group of clients are now participating in the program. I want to revisit the announcement letter to show you how IBM is positioning DB2 11.

Here's how IBM highlights the benefits of DB2 11:

• Helps save money and time how reducing costs.
• Provides unmatched availability, reliability and security for business critical information.
• Provides enhanced analytics for business growth.
• Offers simpler, faster migration for faster ROI.

And here's IBM's list of key features:

• CPU reductions and performance improvements for certain OLTP, heavy insert, select query workloads, and when running queries against compressed tables.
• Improved data sharing performance and efficiency.
• Improved utility performance and additional zIIP eligible workload.
• Cost-effective archiving of warm and cold data with easy access to both within a single query
• Intelligent statistics gathering and advanced optimization technology for efficient query execution in dynamic workloads.
• Additional online schema changes that simplify management, reduce the need for planned outages, and minimize the need for REORG.
• Productivity improvements for DBAs, application developers and system administrators.
• Efficient real-time scoring within your existing transaction environment.
• Enhanced analysis, forecasting, reporting and presentation capabilities, as well as improved storage management, in QMF.
• Expanded SQL, SQL PL, temporal and XML function for better application performance.
• Faster migration with application protection from incompatible SQL and XML changes and simpler catalog migration.

DB2 10 for z/OS is one of the most quickly adopted releases ever. Of course a big factor in this was IBM's decision to allow customers to migrate directly from DB2 8 to DB2 10. Still, DB2 10 is also noteworthy because it dramatically reduced CPU usage. IBM is claiming that DB2 11 will offer just as significant CPU savings -- in the range of 5 to 20 percent. This time though, customers will have to migrate to DB2 10 before moving onto DB2 11.

One thing I like about DB2 11 is its support of an extended RBA. Read this Robert Catterall post for a good explanation of this feature.

Some other quick highlights: The addition of DROP COLUMN should continue to improve online schema changes. New online data repartitioning is designed to significantly reduce the need for planned outages. DB2 11 also brings performance enhancements with long running BIND and DDL threads and improved clone table management and more efficient data sharing. Finally, with DB2 11 applications with SQL or XML will be able to run in compatibility mode, even if they're incompatible with the new release.

So is your company planning on adopting DB2 11 for z/OS soon, and if so, what's driving your decision? Please share your thoughts in comments.

The World of DB2 for z/OS

One of my goals with this blog is to inform you of various DB2 educational and informational resources like IBM Redbooks and, of course, other blogs.

If you're interested in DB2 for z/OS information as well as interacting with other DB2 professionals, you should check out The World of DB2 for z/OS. IBMer Surekha Parekh maintains the site, which offers some great information and features.

To make full use of The World of DB2 for z/OS, you'll need to register (this can be done manually or through an existing account like Facebook, Twitter and Google) and provide some basic information about your company's computing environment and use of and plans for DB2.

One thing I like about The World of DB2 is its chat function. Perhaps you'll recognize someone online, or maybe you'll start a new relationship. Other features include:

 

• My Page – Post comments and check for responses to your comments.
• Events – This is a central place to see all the difference DB2 community events happening around the world.
• Photos – View photos taken at different events and leave comments.
• Wordpress – A list of postings by Surekha.
• Leaderboards – Lists of the top content, members, events and posts.
• Twitter – List of postings related to DB2 10.
• Members – Member list.
• Polldaddy – Poll questions Questions being asked about what topics you want more information on.
• DB2 RUGs – Groups can add themselves to the list and create a virtual meeting place. When I checked there was only one group (Kolkata User Group). Hopefully this will expand as we go.

You'll also find links to IBM developerWorks (DB2 Hotline), the IBM Db2 for z/OS Library (DB2 Library) and various IBM marketing pages.

Incidentally, this week I'm attending the IDUG DB2 Tech Conference. If you're in Orlando, stop by the CA booth and say hi.

IBM Hosts a Big Day for Big Data

I was honored to be invited to IBM Almaden research center in San Jose, California, for a briefing on IBM’s Big Data launch earlier this month. Hundreds of DB2 community luminaries -- including Information Champions, analyst and DB2 Gold Consultants -- were brought together to absorb all this information and then share it with the IT industry through their blogs, articles and tweets.

I learned a lot about what is going on in the distributed world from the discussion of tools like Hadoop as well as the latest DB2 for LUW release. DB2 for LUW 10.5 features a technology called BLU, which supports data stored in columnar format rather than row format. That is, the data page contains data for a given column where row format is rows of data that are stored on a page of data. This column format can dramatically increase the speed of analytic queries.

Of course, with my focus on the mainframe, I wanted to learn more about big data on z/OS. The starting point here was the latest release of DB2 Analytics Accelerator (IDAA) for z/OS, IDAA V3.1.

Prior to IDAA V3.1, data had to be stored on the local host and replicated to the IDAA (Netezza). However, IDAA V3.1 features a High-Performance Storage Saver (HPSS), which allows you to store a DB2 table partition or full table of data solely on the accelerator, reducing the need for host storage. This feature removes the requirement for data to be replicated in DB2 storage and Accelerator storage. Tables can now be divided between traditional database resident partitions on DB2 for z/OS and HPSS on the IDAA.

What are your company's plans for big data? How do you see big data impacting your job as a DBA? Please share your thoughts in comments.