Thursday, April 02, 2020

A Condensed 35-Year History of DB2 for z/OS (...and Db2 for z/OS)


Let's go back in time... over three decades ago... back to the wild and woolly 1980s! And watch our favorite DBMS, DB2, grow up over time.

DB2 Version 1 Release 1 was announced on June 7, 1983, and it became generally available on Tuesday, April 2, 1985. I wonder if it was ready on April 1st but not released because of April Fool’s Day? Initial DB2 development focused on the basics of making a relational DBMS work. Early releases of DB2 were viewed by many as an “information center” DBMS, not for production workloads, like IMS was.

Version 1 Release 2 was announced on February 4, 1986 and was released for general availability a month later on March 7, 1986. Can you imagine waiting only a month for a new release of DB2 these days? But that is how it happened back then. Same thing for Version 1 Release 3, which was announced on May 19, 1987 and became GA on June 26, 1987. DB2 V1R3 saw the introduction of DATE data types.

You might notice that IBM delivered “releases” of DB2 back in the 1980s, whereas today (and ever since V3) there have only been versions. Versions are major changes, whereas releases are not quite as significant as a version.

Version 2 Release 1 was announced in April 1988 and delivered in September 1988. Here we start to see the gap widening again between announcement and delivery. V2R1 was a significant release in the history of DB2, a bellwether of sorts for when DB2 began to be viewed as capable of supporting mission-critical, transaction processing workloads. Not only did V2R1 provide significant performance enhancements but it also signaled the introduction of declarative Referential Integrity (RI) constraints.

No sooner than V2R1 became GA than IBM announced Version 2 Release 2 on October 4, 1988. But it was not until a year later that it became generally available on September 23, 1988. DB2 V2R2 again bolstered performance in many ways. It also saw the introduction of distributed database support (private protocol) across MVS systems.

Version 2 Release 3 was announced on September 5, 1990, and became generally available on October 25, 1991. Two very significant features were added in V2R3: segmented table spaces and packages. Segmented table spaces quickly became a de facto standard and packages made DB2 application programs easier to support. DB2 V2R3 is also the version that beefed up distributed support with Distributed Relational Database Architecture (DRDA).

Along comes DB2 Version 3, announced in November 1993 and GA in December 1993. Now it may look like things sped up again here, but not really. This is when the early support program for DB2 started. Early support was announced in March 1993 and delivered to customers in June 1993. V3 greatly expanded the number of buffer pool options available (from 5 pools to 80), and many advances were made for DB2 to take better advantage of the System 390 environment, including support for hardware-assisted compression and hiperpools. It was also V3 that introduced I/O parallelism for the first time.

Version 4 signaled another significant milestone in the history of DB2. It was highlighted by the introduction of Type 2 indexes, which removed the need to lock index pages (or subpages, now obsolete). Prior to V4, index locking was a particularly thorny performance problem that vexed many shops. Data Sharing made its debut in V4, too, and with it, DB2 achieved new heights of scalability and availability allowing users to upgrade without an outage and to add new subsystems to a group “on the fly.” DB2 V4 also introduced stored procedures, as well as CP parallelism.

In June 1997 DB2 Version 5 became generally available. It was the first DB2 version to be referred to as DB2 for OS/390 (previously it was DB2 for MVS). Not as significant as V4, we see the trend of even-numbered releases being bigger and more significant than odd-numbered releases (of course, that is just my opinion). V5 was touted by IBM as the e-business and BI version. It included Sysplex parallelism, prepared statement caching, reoptimization, online REORG, and conformance to the SQL-92 standard.

Version 6 brings us to 1999 and the introduction of the Universal Database term to the DB2 moniker. The “official” name of the product became DB2 Universal Database for OS/390. And the Release Guide swelled to over 600 pages! Six categories of improvements were introduced with V6 spanning object-relational extensions, network computing, performance and availability, capacity improvements, data sharing enhancements, and user productivity. The biggest of the new features were SQLJ, inline statistics, triggers, large objects (LOBs), user-defined functions, and distinct types.

Version 6 is also somewhat unique in that there was this “thing” typically referred to as the V6 refresh. It added functionality to DB2 without there being a new release or version. The new functionality in the refresh included SAVEPOINTs, identity columns, declared temporary tables, and performance enhancements (including star join).

March 2001 brings us to DB2 Version 7, another “smaller” version of DB2. Developed and released around the time of the Year 2000 hubbub, it offered much-improved utilities and some nice new SQL functionality including scrollable cursors, limited FETCH, and row expressions. Unicode support was also introduced in Db2 V7.

DB2 Version 8 followed, but not immediately. IBM took advantage of Y2K and the general desire of shops to avoid change during this period to take its time and deliver the most significant and feature-laden version of DB2 ever. V8 had more new lines of code than DB2 V1R1 had total lines of code!

With DB2 9 for z/OS, we drop the “V” from the name. Is that in response to Oracle’s naming conventions? Well, we do add a space between the DB2 and the version number because we don’t want to talk about DB-twenty-nine! A lot of great new functionality comes with DB2 9 including additional database definition on demand capabilities, binary data types, and a lot of new SQL capabilities including OLAP functions and EXCEPT/INTERSECT. But probably the biggest new feature is pureXML, which allows you to store DB2 data as native XML. The XML is stored natively as a new data type that can be searched and analyzed without the need to reformat it. The approach was novel in that it  supports native XML, basically enabling dual storage engines.

And that brings us to DB2 10 for z/OS. This version of DB2 was built to take advantage of many zEnterprise (the latest new mainframe at the time) features to deliver scalability. Examples include improved compression, cache optimization, blades for running the Smart Analytics Optimizer, etc. 

Additional capabilities included many performance improvements (BIND, IN-list, utilities, etc.), hash organized table spaces, high-performance DBATs (DDF threads) forced to use RELEASE COMMIT, parallel index updating, efficient caching of dynamic SQL with literals, temporal data support, safe query optimization, improved access path hints, access to currently committed data, new TIMESTAMP precision and time zones, and buffer pool options for pinning objects in memory.

In October 2013 we got another new version, DB2 11 for z/OS. Click on that link if you want all the details, but some highlights included transparent archiving, global variables, improved SQL PL, APREUSE(WARN), significant utility improvements, DROP COLUMN support, and JSON support with IBM BigInsights.

And that brings us to the present day, with DB2 12 for z/OS as the current (and soon to be only) supported version of Db2. Released for general availability in October 2016, DB2 12 for z/OS abandons the traditional new release cycle that IBM has followed for decades, adopting a new continuous delivery model. New functionality is now delivered in Function Levels (FLs) that are easily applied and delivered much more rapidly than in the past. Indeed, the current Db2 function level is FL506, which means there have been 6 new function levels added since 2016.

Version 12 brought with it a plethora of new capabilities including virtual storage enhancements, optimization improvements, and improved control over the introduction of new SQL capabilities. DB2 12 for z/OS delivered many improvements for both application development and database administration. Examples of new application capabilities include:
  • Additional support for triggers, arrays, global variables, pureXML, and JSON
  • MERGE statement enhancements
  • SQL pagination support
  • Support for Unicode columns in an EBCDIC table
  • Piece-wise deletion of data
  • Support for temporal referential constraint
  • More flexibility in defining application periods for temporal tables
  • PERCENTILE function support
  • Resource limits for static SQL statements
  • Db2 REST services improve efficiency and security
  • DevOps with Db2: Automated deployment of applications with IBM UrbanCode Deploy
Examples of new DBA and SYSADM capabilities include:

  • Installation or migration without requiring SYSADM
  • Improved availability when altering index compression
  • Online schema enhancements
  • Improved catalog availability
  • Object ownership transfer
  • Improved data validation after running DSN1COPY
  • Automatic start of profiles at Db2 start
  • Increased partition sizes and simplified partition management for partition-by-range table spaces with relative page numbering
  • Ability to add partitions between existing logical partitions
  • UNLOAD privilege for the UNLOAD utility
  • Temporal versioning for Db2 catalog tables
  • Statistics collection enhancements for SQL performance    
Of course, these are just some of the V12 improvements; there are many more (as well as all of the Function Level improvements)!

Then sometime in the middle of 2017, IBM decided to change the name of DB2 by making the uppercase B a lowercase b. So now the name of our beloved DBMS is Db2. Nobody has been able to explain to me what the benefit of this was, so don’t ask me!

The Bottom Line

I worked with DB2 way back in its Version 1 days, and I’ve enjoyed watching DB2 grow over its first 35 years. Of course, we did not cover every new feature and capability of each version and release, only the highlights. Perhaps this journey back through time will help you to remember when you jumped on board with Db2 and relational database technology. I am happy to have been associated with Db2 (and DB2) for its first 35 years and I look forward to many more years of working with Db2… 

Tuesday, March 24, 2020

IDUG NA 2020 Conference Cancelled

I just received an e-mail notifying me that the 2020 IDUG Db2 Tech Conference scheduled for the week of June 7th in Dallas, TX has been canceled. This is the first time that IDUG has had to cancel a conference, but I have to congratulate the Conference Planning Committee and Board of Directors for making this difficult, but absolutely correct decision.

The email went on to say that IDUG is exploring all of its options for rescheduling the conference for a future date. And they assured all speakers that their sessions are still being held on the grid... so if you want to speak if and when the conference gets re-scheduled, you can!

The global COVID-19 pandemic has impacted all of our daily lives and for the Db2 community, this is just one more reminder of how pervasive this impact has been.

Let's all keep the faith and do our part (stay home, wash your hands) to shorten the duration of this global pandemic...

And Long Live Db2!!!

Tuesday, March 10, 2020

A Guide to Db2 Performance for Application Developers



DBAs: are you looking for a way to help train your developers to code more efficient Db2 application programs? 
Programmers: do you want to understand the best practices for writing high-performing Db2 applications?
Well, my latest book, A Guide to Db2 Performance for Application Developers, is just what you are looking for! Available in both printed and eBook formats, this is the book you need to assure that you are building effective, efficient Db2 applications.


This book will make you a better programmer by teaching you how to write efficient code to access Db2 databases. Whether you write applications on the mainframe or distributed systems, this book will teach you practices, methods, and techniques for optimizing your SQL and applications as you build them. Write efficient applications and become your DBA's favorite developer by learning the techniques outlined in this book!

The methods outlined in this book will help you improve the performance of your Db2 applications. The material is written for all Db2 professionals, whether you are coding on z/OS (the mainframe) or on Linux, Unix or Windows (distributed systems). When there are pertinent differences between the platforms it is explained in the text.

The focus of the book is on programming, coding and developing applications. As such, it does not focus on DBA, design, and data modeling issues, nor does it cover most Db2 utilities, DDL, and other non-programming related details. If you are a DBA, the book should still be of interest to you because DBAs are responsible for overall Db2 performance. Therefore, it makes sense to understand the programming aspect of performance.

It is important also to understand that the book is not about performance monitoring and tuning. Although these activities are important, they are typically not the domain of application developers. Instead, the book offers guidance on application development procedures, techniques, and philosophies. The goal of the book is to educate developers on how to write "good" application code that lends itself to optimal performance. By following the principles in this book you will be able to write code that does not require significant remedial, after-the-fact modifications by performance analysts. If you follow the guidelines in this book your DBAs and performance analysts will love you!

The assumption is made that the reader has some level of basic SQL knowledge and therefore it will not cover how to write Db2 SQL code or code a Db2 program. It is also important to point out that the book does not rehash material that is freely available in Db2 manuals that can be downloaded or read online.

What you will get from reading this book is a well-grounded basis for designing and developing efficient Db2 applications that perform well.

You can order your copy of A Guide to Db2 Performance for Application Developers today at:

Monday, February 17, 2020

Every Db2 Article I've Written

I've written a lot of articles on Db2 topics over the years and I try to keep everything I've written available over the web. Some of the older articles may not be as applicable today as they were in the past, but I still try to keep them available in case somebody remembers reading something and they want to be able to find it again. 

So, if you are ever want to find a Db2 article of mine that you've read and want to see again, try the following link:

http://www.mullinsconsulting.com/art-db2.html

That page contains all of the Db2 articles that I've written and most of them have links to the full article. It is in reverse chronological order...

And just for fun... here's a picture of the old demo floppy disk that used to come with Db2 back in the day!




Wednesday, February 12, 2020

Will I See You at SHARE in Fort Worth 2020?


I hope you’ve already made your plans to be there, but if you haven’t there’s still time to get your manager’s approval, make your travel plans, and be where all the in-the-know IT folks will be the last week of February, the SHARE conference in Fort Worth, Texas!

If you’ve ever attended a SHARE conference before then you know why I’m looking forward to this event. With 300+ industry speakers, 500+ sessions and 1,000+ attendees, SHARE offers a world of phenomenal educational opportunities delivered by renowned industry leaders. If you attend, you can benefit from user-driven technical sessions, insights from colleagues, and hardware and software product education all in one place. SHARE attendance guarantees you access to the latest enterprise IT news, prominent industry leaders — including IBM executives — and product highlights on emerging technologies, bringing priceless value to your daily work.

The Spring 2020 event offers more educational opportunities and training than ever before, including content that spans 8 IT disciplines, including:
  • Application Development
  • Database Systems
  • Middleware
  • Networks
  • Operating Systems (z/OS, z/VM, Linux)
  • Security
  • Storage
  • Systems Management

SHARE began as the first-ever enterprise IT user group way back in 1955… but it has continued to grow and expand over the years> Today it offers an unparalleled opportunity to learn about enterprise IT and to interact with your peers.

What Will I Be Doing SHARE?

As usual, I hope to attend many different sessions to learn what is new out there, especially with regard to my core areas (mainframe and Db2). Check out the agenda here.

I also will be delivering a Lunch and Learn session this year, sponsored by Infotel, on Tuesday, February 25, 2020. This presentation, titled Improving Db2 Application Quality for Optimizing Performance and Controlling Costs, will be presented with a free lunch! So be sure to sign up, then come eat and at the same time, learn about the impact of DevOps on database. I’ll talk about the issues and trends then Colin Oakhill of Infotel will discuss how their SQL quality assurance solutions can aid the DevOps process for Db2 development.

You can RSVP for Lunch and Learn sessions by using the link provided during the registration process. Pre-registration is highly encouraged and space is available on a first-come, first-served basis. If you have already registered and did not RSVP, you can log in to your registration and add your RSVP.
If you have not RSVPed you can still attend the Lunch and Learn session, on a first-come, first-serve basis. Seating opens up to everyone at 12:35 p.m. (10 minutes prior to the session start time).
Later that evening (Tuesday) on the second day of the SHARE expo hall I'll be hanging at the Infotel booth, so if you have any questions we didn’t answer in the Lunch n’ Learn session, you can ask us at the Infotel booth. Be sure to stop by and say hello, take a look at Infotel’s SQL quality assurance solutions for Db2 for z/OS, and register to win one of 2 of my Db2 application performance books that will be raffled off. If you win, be sure to get me to sign your copy!

The Bottom Line

SHARE is the place to be this February 2020 to learn all about what’s going on in the world of enterprise computing. I hope to see you in Fort Worth for SHARE… and if you are going, be sure to track me down and say “Howdy!”



Thursday, February 06, 2020

IBM Gold Consultant for Data and AI :: 2020

I am proud to announce that I will be continuing as an IBM Gold Consultant for Data and AI in 2020

For those of you who do not know what an IBM Gold Consultant is... the IBM Gold Consultant program is an elite group of independent consultants with vast experience in IBM data repositories, unified governance, artificial intelligence (AI) and machine learning.

IBM Gold Consultants bring extensive industry experience and technical expertise to help IBM clients define and implement strong strategies for their data and analytics initiatives using IBM Db2 on all platforms, IBM Informix, IBM InfoSphere, IBM CICS, and related technologies and tools. The group is recognized by its peers, and IBM, as some of the world’s most experienced independent consultants for these products. 

Thank you, IBM, for creating such great data management tools and solutions that I have been able to build a career - spanning more than three decades - using them.



Mullins Consulting, Inc.

Friday, January 03, 2020

Db2 11 for z/OS End of Support Coming This Year (2020)

What better way to start off the New Year than with a quick blog post to remind everybody that the end of service deadline is looming for Db2 11 for z/OS... and that means it is time for you to move to Db2 12 for z/OS this year!


Version 11 of our favorite DBMS was made generally available way back on October 25, 2013 and IBM has not been marketing and selling this version since July of 2018. But if you are still using Db2 11 IBM has continued to provide support... and will continue for the first three quarters of 2020. But after that, support ends.

In other words, the end of support date for Db2 11 for z/OS is September 30, 2020. And that date appears to be a firm one... don't bet on IBM extending it.

Whtat does that mean for you if you are still using Version 11? It should mean that you will be spending the first three quarters of 2020 planning for, and migrating to Db2 12 for z/OS.

There are a lot of great resources that IBM provides to help you migrate smoothly. Here are a few of them for you reference:

  Db2 12 Installation and Migration Guide

  Db2 12 for z/OS Product Documentation

  Webcast: Db2 12 for z/OS Migration Planning and Customer Experiences with John Campbell

  Db2 12 for z/OS Migration Considerations (Mark Rader)

So if you are still running Db2 11 and you haven't started planning to upgrade, now is the time to start planning... and if you have started planning, that is great, because 2020 is the time to get your shop migrated to Db2 12!

Friday, December 27, 2019

Planning Your Db2 Performance Monitoring Strategy


The first part of any Db2 performance management strategy should be to provide a comprehensive approach to the monitoring of the Db2 subsystems operating at your shop. This approach involves monitoring not only the threads accessing Db2 and the SQL they issue, but also the DB2 address spaces. 

There are three aspects that must be addressed in order to accomplish this task:
  • Batch reports run against Db2 trace records. While Db2 is running, you can activate traces that accumulate information, which can be used to monitor both the performance of the Db2 subsystem and the applications being run. For more details on Db2 traces see my earlier 2-part blog post (part 1, part 2).
  • Online access to Db2 trace information and Db2 control blocks. This type of monitoring also can provide information on Db2 and its subordinate applications.
  • Sampling Db2 application programs as they run and analyzing which portions of the code use the most resources.

There are many in-depth details that comprise the task of setting these three components up to efficiently and effectively monitor your Db2 activity. I go over these details in my book, Db2 Developers Guide, so I direct interested parties there for the gory details.

But let's go over some performance monitoring basics. When you’re implementing a performance monitoring methodology, keep these basic caveats in mind:
  • Do not overdo monitoring and tracing. Db2 performance monitoring can consume a tremendous amount of resources. Sometimes the associated overhead is worthwhile because the monitoring (problem determination or exception notification) can help alleviate or avoid a problem. However, absorbing a large CPU overhead to monitor a Db2 subsystem that is already performing within the desired scope of acceptance might not be worthwhile.
  • Plan and implement two types of monitoring strategies at your shop:
  1. ongoing performance monitoring to ferret out exceptions, and;
  2. procedures for monitoring exceptions after they have been observed.
  • Do not try to drive a nail with a bulldozer. Use the correct tool for the job, based on the type of problem you’re monitoring. You would be unwise to turn on a trace that causes 200% CPU overhead to solve a production problem that could be solved just as easily by other types of monitoring (e.g. using EXPLAIN or Db2 Catalog reports).
  • Tuning should not consume your every waking moment. Establish your Db2 performance tuning goals in advance, and stop when they have been achieved. Too often, tuning goes beyond the point at which reasonable gains can be realized for the amount of effort exerted. (For example, if your goal is to achieve a five-second response time for a TSO application, stop when you have achieved that goal instead of tuning it further even if you can.)

Tuning goals should be set using the discipline of service level management (SLM). A service level is a measure of operational behavior. SLM ensures applications behave accordingly by applying resources to those applications based on their importance to the organization. Depending on the needs of the organization, SLM can focus on availability, performance, or both. In terms of availability, the service level can be defined as “99.95% uptime, during the hours of 9:00 AM to 10:00 PM on weekdays.” Of course, a service level can be more specific, stating “average response time for transactions will be two seconds or less for workloads of 500 or fewer users.”

For a service level agreement (SLA) to be successful, all of the parties involved must agree upon stated objectives for availability and performance. The end-users must be satisfied with the performance of their applications, and the DBAs and technicians must be content with their ability to manage the system to the objectives. Compromise is essential to reach a useful SLA.

If you do not identify service levels for each transaction, then you will always be managing to an unidentified requirement. Without a predefined and agreed upon SLA, how will the DBA and the end-users know whether an application is performing adequately? Without SLAs, business users and DBAs might have different expectations, resulting in unsatisfied business executives and frustrated DBAs... Not a good situation.

Wednesday, December 18, 2019

High Level Db2 Indexing Advice for Large and Small Tables


In general, creating indexes to support your most frequent and important Db2 SQL queries is a good idea. But the size of the table will be a factor in decided whether to index at all and/or how many indexes to create.

For tables more than 100 (or so) pages, it usually is best to define at least one index. This gives Db2 guiidance on how to cluster the data. And, for the most part, you should follow the general advice of having a primary key for every table... and that means at least one unique index to support the primary key.

If the table is large (more than 20,000 pages or so), you need to perform a balancing act to limit the indexes to those absolutely necessary for performance. When a large table has multiple indexes, data modification performance can suffer. When large tables lack indexes, however, access efficiency will suffer. This fragile balance must be monitored closely. In most situations, more indexes are better than fewer indexes because most applications are query-intensive rather than update-intensive. However, each table and application will have its own characteristics and requirements.

For tables containing a small number of pages (up to 100 or so pages) consider limiting indexes to those required for uniqueness and perhaps to support common join criterion. This is a reasonable approach because such a small number of pages can be scanned as, or more, efficiently than using an index.

For small tables you can add indexes when the performance of queries that access the table suffers. Test the performance of the query after the index is created, though, to ensure that the index helps. When you index a small table, increased I/O (due to index accesses) may cause performance to suffer when compared to a complete scan of all the data in the table.

Tuesday, December 03, 2019

A Guide to Db2 Application Performance for Developers: A Holiday Discount!

Regular readers of my blog know that I have written a couple of Db2 books, including DB2 Developer's Guide, which has been in print for over 20 years across 6 different editions. But you may not be aware that I recently wrote a new Db2 book, this time focusing on the things that application programmers and developers need to do to write programs that perform well from the very start. This new book is called A Guide to Db2 Application Performance for Developers.



You see, in my current role as an independent consultant that focuses on data management issues and involves a lot of work with Db2, I get to visit a lot of different organizations... and I get to see a lot of poorly performing programs and applications. So I thought: "Wouldn't it be great if there was a book I could recommend that would advise coders on how to ensure optimal performance in their code as they write their Db2 programs?" Well, now there is... 
A Guide to Db2 Application Performance for Developers.

This book is written for all Db2 professionals, covering both Db2 for LUW and Db2 for z/OS. When there are pertinent differences between the two it will be pointed out in the text. The book’s focus is on develop­ing applications, not database and system administration. So it doesn’t cover the things you don’t do on a daily basis as an application coder.  Instead, the book offers guidance on application devel­opment procedures, techniques, and philosophies for producing optimal code. The goal is to educate developers on how to write good appli­cation code that lends itself to optimal performance. 

By following the principles in this book you should be able to write code that does not require significant remedial, after-the-fact modifications by performance ana­lysts. If you follow the guidelines in this book your DBAs and performance analysts will love you!

The book does not rehash material that is freely available in Db2 manuals that can be downloaded or read online. It is assumed that the reader has access to the Db2 manuals for their environment (Linux, Unix, Windows, z/OS).

The book is not a tutorial on SQL; it assumes that you have knowledge of how to code SQL statements and embed them in your applications. Instead, it offers advice on how to code your programs and SQL statements for performance.

What you will get from reading this book is a well-grounded basis for designing and developing efficient Db2 applications that perform well. 

OK, you may be saying, but what about that "Holiday Discount" you mention in the title? Well, I am offering a discount for anyone who buys the book before the end of the year (2019). There are different discounts and codes for the print and ebook versions of the book:


  • To receive a 5% discount on the print version of the book, use code 5poff when you order at this link.
  • To receive $5.00 off on the ebook version of the book, user code 5off when you order at this link.
These codes only work on the Bookbaby site. You can, of course, buy the book at other book stores, such as Amazon, at whatever price they are currently charging!


Happy holidays... and why not treat the programmer in your life to a copy of A Guide to Db2 Application Performance for Developers?  They'll surely thank you for it.



Wednesday, November 27, 2019

Happy Thanksgiving 2019

Just a quick post today to wish all of my readers in the US (and everywhere, really) a very Happy Thanksgiving.



Thanksgiving is a day we celebrate in the USA by spending time with family, eating well (traditionally turkey), and giving thanks for all that we have and hold dear.

Oh... and also for watching football!

May all of you reading this have a warm and happy Thanksgiving holiday surrounded by your family and loved one.

Happy Thanksgiving!

Thursday, November 07, 2019

Db2 12 for z/OS Function Level 506

Late last month, October 2019, IBM introduced a new function level, FL506, for Db2 12 for z/OS.  There are two significant impacts of this new function level:
  • Alternative function names support
  • Support for implicitly dropping explicitly created table spaces
The first impact, support for additional, alternative names for some existing Db2 built-in functions, was added is to improve compatibility across the Db2 product line. It is basically just a new way to refer to existing functionality, an alternative syntax, if you will. The following chart outlines the existing and new FL506 alternative syntax.

Table 1. Alternative Syntax for Function Names in FL506        
Existing Function Name
New Alternative Syntax Name
CHARACTER_LENGTH
CHAR_LENGTH
COVARIANCE or COVAR
COVAR_POP
HASH_MD5 or HASH-SHA1 or HASH_SHA256
HASH
POWER
POW
RAND
RANDOM
LEFT
STRLEFT
POSSTR
STRPOS
RIGHT
STRRIGHT
CLOB
TO_CLOB
TIMESTAMP_FORMAT
TO_TIMESTAMP


Support for these alternative spelling of built-in function names should make it easier to support applications across multiple members of the Db2 family where support already exists for these spellings. Of course, you may run into issues if you used any of the new spellings in your existing applications, for example as variable names.

The other significant feature of FL506 is support for implicitly dropping explicitly created universal table spaces when a DROP TABLE statement is executed. Prior to FL506 dropping a table that resides in an explicitly created table space does not drop the table space.

If you use vendor tools that manage and generate scripts for DDL changes, they need to be modified to support FL506. If not, they could produce -204 SQL codes when the generated DDL is executed if the DDL contains a DROP TABLESPACE statement. The table space will have already been implicitly dropped and trying to drop a table space that does not exist will throw an error. Be sure to discuss this with your tools vendor before migrating to FL506 to understand the cendor’s support timeline or if they have a workaround.

Summary

IBM is using function levels to deliver significant new capabilities for Db2 12 for z/OS. It is important for you and your organization to keep up-to-date on this new functionality and to determine where and when it makes sense to introduce it into your Db2 databases and applications.

Also, be aware that if you are not currently running at FL505, moving to FL506 activates all earlier function levels. You can find a list of all the current function levels here.




Thursday, October 31, 2019

Have You Considered Speaking at the IDUG Db2 Technical Conference? You should!

The 2020 North American Db2 Technical Conference is being held in Dallas, TX the week of June 7th. And the call for papers is still open and IDUG is looking for Db2 folks who want to share their experiences with Db2. You can talk about a project you worked on, an experience you had tuning or optimizing your Db2 databases and applications, your experience implementing a new version or funtion level, how your team uses any Db2 feature or capability, or really, anything related to your experience with Db2.

Speaking at a user group is a good way to expand your contacts and develop additional personal interaction skills. And I have also found it to be a good way to increase my technical knowledge and skills. Sure, as the presenter you are sharing your knowledge with the audience, but it always seems like I expand my knowledge and way of thinking about things when I deliver a presentation. Either because of questions I receive, or because putting the presentation together made me stop and think about things in different ways.

And if you are accepted to speak your attendance at the conference is complimentary!

Putting together an abstract is not that difficult at all. You just need to complete a bit of biographical information about yourself, select a category for your presentation, provide an overview of your topic, and offer up a bulleted list of 5 objectives. The site guides you through submitting all of these things at this link.

Speaking at a conference can be a very rewarding experience... and once you start doing it, you'll want to do it again and again. So go ahead. Click here and submit your abstract and I hope I'll see you in Dallas in June 2020!

Thursday, October 17, 2019

See You in Rotterdam... at the IDUG Db2 Tech Conference

Next week the 2019 IDUG EMEA Db2 Tech Conference is coming to Rotterdam and I am looking forward to being there. This year’s event is being held the week of October 20-24, 2019. I hope you’ve already made your plans to be there, but if you haven’t there’s still time to get your manager’s approval, make travel plans, and be where all the Db2 folks will be the end of October.

If you’ve ever attended an IDUG conference before then you know how much useful information you can learn at the event. IDUG offers phenomenal educational opportunities delivered by IBM developers, vendor experts, users, and consultants from all over the world. There will be a slew of informative technical sessions on all of the latest and greatest Db2 technologies and features. 

And let's not forget the exhibit hall (aka Solutions Center) where vendors present and demo their products that can help you manage Db2 more effectively. It is a good place to learn about new technology solutions for Db2, but also to hang out and meet with IBMers, consultants, and your peers.

If you have any doubts whether there will be something worthwhile for you there just take a look at this packed agenda! One of the conference highlights is always the great keynote session. This year's will be delivered by Al Martin, IBM VP of Development for Db2 Z and Warson Tool. He will talk about business and strategy for data and AI, highlighting how data is the foundation for AI. Should be informative and entertaining!

What Am I Up to at IDUG?

As usual, I will be busy at the conference. I will be arriving early into Rotterdam so I can get over the jet lag and then participate in some pre-conference meetings on Sunday. 

There are a couple of opportunities for you to stop by and say "Howdy!" to me, and I hope you will take advantage of them. On Tuesday, at 3:20 PM, I will be delivering a vendor-sponsored presentation (or VSP) for InfotelThis presentation, titled Improving Db2 Application Quality for Optimizing Performance and Controlling Costs. My portion of the presentation focuses on the impact of DevOps on database; it will be followed up by Colin Oakhill of Infotel-Insoft, who will talk about how their SQL quality assurance solutions can aid the DevOps process for Db2 development.

Additionally, Tueday evening I'll be spending some time in the booth with Infotel. So if you have any questions we didn’t answer in the VSP, you can ask us at the Infotel booth. Be sure to stop by and say hello, take a look at Infotel’s SQL quality assurance solutions for Db2 for z/OS, and register to win one of 2 of my Db2 application performance  books that will be raffled off. If you win, be sure to get me to sign your copy!

A Guide to Db2 Performance for Application Developers


Just Look at All That IDUG Has to Offer!

You can go to free complimentary workshops and hands-on labs being held throughout the duration of the conference. These half-day and full-day sessions are packed full of useful information that you can take home and apply to your Db2 environment. And this year there are sessions on Db2 migration, Db2 and the cloud, problem determination, machine learning, Zowe, and more. So be sure to track down the workshops that you want to attend and register for them before they fill up!

If you are looking for Db2 certification then IDUG is the place to be! All IDUG attendees can recive two complimentary certification coupons to take any IBM certification exams (to be completed at your leisure, as long as they are used before June 30, 2020).

And don't miss the Expert Panels where IBMers and other subject matter experts answer your questions. There are three separate panels this year covering Db2 for z/OS, Db2 for LUW and Application Development.

Finally, be sure that you download the mobile app for the conference to help you navigate all the opportunities available to you! Armed with the mobile app you’ll get daily intel on what’s happening at the conference.

Justifying Your Attendance

Finally, if you need any help justifying your attendance at this year’s IDUG event, just use this justification letter as your template to create an iron-clad rationale for your boss.

The Bottom Line

The IDUG Db2 Tech Conference is the place to be to learn all about Db2 from IBMers, gold consultants, IBM champions, end users, ISVs, and more. With all of this great stuff going on this year in Rotterdam, why would you want to be any place else!?!?