Just a quick post to apologize for not posting here as often as I would like. I have been traveling quite a lot the past month or so and just haven't had the time to keep up with everything while I've been on the road. But don't give up on me... I'll be back and blogging here again after the New Year.In the meantime, be sure to check in regularly on my other blog, Data Management Today.And if you live in Richmond or Detroit, you can see me present at your local user group next week... Tuesday in Richmond (12/9/08) and Thursday in Detroit (12/1...
Sunday, 7 December 2008
Friday, 14 November 2008
Just a quick entry today to remind everyone that IDUG has started conducting regional events. The first one was held last week in San Ramon, California, and next week two events will be held: in Camp Hill, Pennsylvania, and Kansas City, Missouri, (actually Lenexa, KS). The forums offer you an opportunity to obtain DB2 education rather quickly and inexpensively.Each Forum offers 2 days of education with 2 tracks: one covering DB2 for z/OS and another covering DB2 for LUW. IDUG is offering full two day registrations for $425 and single day registrations...
Friday, 7 November 2008
DB2 allows you to add and subtract DATE, TIME, and TIMESTAMP columns. In addition, you can add date and time durations to, or subtract them from, date and time columns. But use date and time arithmetic with care. If you do not understand the capabilities and features of date and time arithmetic, you will likely encounter some problems implementing it. Keep the following rules in mind. When you issue date arithmetic statements using durations, do not try to establish a common conversion factor between durations of different types. For example,...
Thursday, 6 November 2008
If you are at all involved in assuring the quality of your company’s data you need to know the work of Thomas C. Redman. Dr. Redman has been working on improving data quality for years and he has written numerous articles and books on the subject. His latest book, Data Driven: Profiting From Your Most Important Business Asset is another winner.Redman offers the basic thesis of the book right there on page one, where he states “…bad data lie at the root of issues of international importance, including the current subprime mortgage meltdown, lost...
Monday, 3 November 2008
Here is a follow-up question and answer based on my previous blog post:Q: My format does not fit into any of the formats listed in the DB2 manuals. What if I have a DATE stored like YYYYMMDD (with no dashes or slashes) and I want to compare it to a DB2 date? A: Okay, let's look at one potential solution to your problem (and then I want to briefly talk about the use of proper data types). First of all you indicate that your date column contains dates in the following format: yyyymmdd with no dashes or slashes. You do not indicate whether this field...
Tuesday, 28 October 2008
Regular readers of my blog know that from time to time I use the blog as a forum to answer questions I get via e-mail. Today, we address a popular theme - dealing with DB2 date data...Q:I have a DATE column in a DB2 table, but I do not want it to display the way DB2 displays it by default. How can I get a date format retrieved from a column in a table from DB2 database in the format MM/DD/YYYY?A:The simplest way to return a date in the format you desire is to use the built-in column function CHAR. Using this function you can convert a date column...
Wednesday, 22 October 2008
Monday, 20 October 2008
Database administration is a very technical discipline, but it is also a discipline in which the practitioner is very visible politically within the organization. As such, DBAs should be armed with the proper attitude and knowledge before attempting to practice the discipline of database administration.Just as important as technical acumen, though, is the ability to carry oneself properly and to embrace the job appropriately. With this in mind, I wrote a series of blog entries on DBA Rules of Thumb over at my Data Management Today blog... and I...
Thursday, 9 October 2008
Availability requires much more than just having a reliable hardware and database platform. Most companies cannot afford significant downtime, and some cannot afford any! As such, it is crucial for unplanned outages to be as short as possible. But it is not just a business requirement, in many cases assuring a speedy recovery is also a legal mandate. Regulations such as SOX and Basel II dictate that any outage is resolved within a predefined period of time.But how many of us can answer, with any degree of certainty, the question “How long will...
Tuesday, 30 September 2008
There is something of a perfect storm brewing in the world of data today. The world is becoming more automated, more connected, more wireless, and more complex. The next wave of database administration is intelligent automation. I refer to this as implementing software scrubbing bubbles that “work hard, so you don’t have to.” (Remember that commercial!)As more of the tasks required of DBAs become more automated, the DBA will be freed to expand into other areas. So one front on this storm is the autonomic computing initiatives that automate DBA...
Tuesday, 23 September 2008
As the list of government regulations impacting IT grows organizations must adapt to understand and comply with new rules. This increasing compliance pressure is particularly intense on data stored in corporate databases. As such, organization need to be ever more vigilant in the techniques used to protect their data, and monitor access.Database auditing, sometimes called data access auditing, is one technique growing in popularity as a response to the demands of regulatory compliance. At a high level, database auditing is basically a facility...
Monday, 22 September 2008
Friday, 5 September 2008
I know that many readers will question the title of this blog posting. But it is true. Oh, many DBAs think that managing performance is the most important thing they do, but they are confusing frequency with importance. Yes, many are managing performance more often than building backup plans – and they better be managing performance more frequently than they are actually recovering their databases or their company has big problems!Anyway, why do I place recoverability at the very top of the DBA task list? Well, if you cannot recover your databases...
Thursday, 4 September 2008
Recently I was reading through some posts in a database-related newsgroup or mailing list (actually, right now I can't remember which one it was). The conversation I was reading was in response to a question like "Does the number of columns or size of the row matter in terms of performance?"Actually, the question asked what kind of a performance impact might be expected if a query was issued against two similar tables. The first table had (say) 20 columns, and the second table had the same 20 columns, as well as 35 additional columns.Well, most...
Wednesday, 3 September 2008
Answering a question I got via e-mail on indexing... Every now and then I take the opportunity to blog about a question I get through e-mail. This time the question was:When does it make more sense not to build an index for a DB2 table? I'll attempt to answer this question for any SQL DBMS, not just for DB2: First of all, this is a very open-ended question, so I will give a high-level answer. Let's start by saying that most of the time you will want to build at least one - and probably multiple - indexes on each database table that you create....
Friday, 22 August 2008
Anyone who has been paying attention lately knows at least something about the large number of data breaches that have been in the news. Data breaches and the threat of lost or stolen data will continue to plague organizations until comprehensive plans are enacted to combat them. Although many of these breaches have not been at the database level, some have, and more will be unless better data protection policies and procedures are enacted on operational databases.If you are interested in this topic I will be conducting a free webinar titled Data...
Monday, 28 July 2008
One of the fun things about publishing is getting questions from readers that make you think. A recent question I received went something like this: "Can I get the odd and even number of rows from a DB2 table?"Well, my first reaction was to think "this guy doesn't understand the way a SQL DBMS like DB2 works." The data in DB2 tables is not ordered, so there is no way to guarantee that the rows are odd or even numbered. While that observation may (or may not) have been true, it didn't help the guy. So I thought about it and came up with a possible...
Thursday, 24 July 2008
Protecting corporate data is a requirement of doing business in today's regulatory and security-minded business environment. Protecting corporate data -- an especially sensitive data -- is a matter of knowing who is accessing data and what are they doing with it. There have been many solutions for addressing this need on distributed databases, but no reasonable solution for protecting mainframe data until now.Learn all about an exciting new solution for auditing your DB2 for z/OS databases and resources - Guardium for Mainframes - at this free...
Monday, 21 July 2008
Just a quick FYI today to let you know about a new RedPaper offering information about exploiting client load balancing and fail over capabilities across a DB2 data sharing group (or a subset of the group members).A RedPaper is sort of like a tip, only longer... and sort of like a RedBook, only shorter... Anyway, if you are interested in the topic, the RedPaper can be donwloaded for free by following this link: DB2 9 for z/OS Data Sharing: Distributed Load Balancing and Fault Tolerant Configurat...
Monday, 7 July 2008
Wednesday, 25 June 2008
Here is a question that was posed to me recently:Q: We have a CHAR(10) column that cannot contain alphabetic characters. How can we make sure that the letters A thru Z are not allowed.A: Well, think about the characteristics of alphabetic characters versus the other "things" that can be stored in a CHAR column. One thing that separates an alphabetic letter from numbers, punctuation, etc. is that there are upper and lower case versions (e.g. A, a). So, you could use the following predicate to preclude alphabetic characters from being accepted:...
Monday, 16 June 2008
Have you seen Gartner's latest report on the middleware market?The Gartner middleware market numbers were reported in a recent article in eWeek. Evidently, the worldwide application infrastructure and middleware software market revenue totaled $14.1 billion in 2007, a 12.9 percent increase from 2006 revenue of $12.5 billion.Now that is quite healthy growth in what is a somewhat slow market. And right there at the top of the pile is IBM with a 28.9 percent share of what Gartner identifies as the AIM market...BEA Systems came in second with 9.3 percent...
Sunday, 8 June 2008
I will been traveling extensively in June this year (2008). Last week I traveled to Phoenix to speak to the American Express Information Summit on the topic of regulatory compliance and its impact on data management and database administration. And I also spoke at the Los Angeles Area DB2 User Group on DB2 performance tuning and database trends.This week (the second week of June) I will be traveling to Washington, DC to speak to the Baltimore-Washington DB2 User Group (BWDUG) on June 11th to deliver "The Impact of Regulatory Compliance on Database...
Wednesday, 28 May 2008
Just a short note to promote my upcoming webinar, this Friday, May 30, 2008 at 10:30 AM CST. The webinar is titled Database Archiving Trends and Best Practices and it will cover a variety of trends and issues that are contributing to the growing requirement within enterprises to archive database data for long-term retention and preservation.I'll touch on trends such as regulatory compliance issues, e-discovery, operational performance improvement, and retiring legacy applications. After examining the forces driving the need to archive database...
Monday, 26 May 2008
Just a quick post today (Memorial Day in the USA) to inform you about a new IBM RedBook on dimensional modeling. If you are working with data warehousing applications, writing analytical queries, or in any way dealing with databases and dimensional models, this free RedBook is well worth downloading and reading.It is titled Dimensional Modeling: In a Business Intelligence Environment. The book is not intended to be an academic treatise, but a practical guide for implementing dimensional models oriented specifically to business intelligence systems.Particularly...
Thursday, 22 May 2008
Well, here it is late in the day on May 22, 2008 and the IDUG North American conference is officially over. And, of course, it was another successful conference!From the start of the festivities on Monday with the welcome address and keynote session (which can be downloaded here) to the traditional IBM panel and closing session today, IDUG offered consistently high quality education and unparalleled networking opportunities for DB2 professionals.Usually I blog about the sessions I attend but this year I used Twitter instead to micro-blog the highlights...
Wednesday, 14 May 2008
After listening to John Dvorak (on Cranky Geeks) talk about Twitter I decided to try it out this week. And I quickly found some other DB2 folks out there twittering (Willie, Troy).I put up Twitter feeds on my home page and here on my blog, too (it is over there on the right). I'm not sure if I'll stick with Twittering long-term, but I probably will - it is a bit addictive. If you want to try it out yourself, click on the follow me on Twitter link over on the right hand side of this page - or click here if you don't want to be bothered tracking...
Monday, 12 May 2008
Just a quick blog entry today to promote my upcoming webinar on May 30, 2008 titled Database Archiving Trends and Best Practices.A variety of trends and issues are contributing to the growing requirement within enterprises to archive database data for long-term retention and preservation. This webinar will review the trends driving database archiving, including regulatory compliance issues, e-discovery, operational performance improvement, and retiring legacy applications. After examining the driving forces for database archiving, we will walk...
Monday, 28 April 2008
If you live in or around Birmingham, Alabama or Dallas, Texas or Phoenix, Arizona I will be in your neck of the woods the next two weeks speaking at the local DB2 user groups.On April 30th, 2008 I'll be speaking at Alabama DB2 User Group on the topic of Managing Data For Long Retention Periods.Then, on May 2nd, I mosey on over to Dallas to speak on two topics at the DB2 Forum meeting. I'll cover database auditing in one talk and the other will be my "famous" DB2 Top 10 Lists presentation.The following week, on May 8th, I'll be in Arizona to discuss...
Tuesday, 22 April 2008
Today I'm posting a quick blog entry to let my readers know about a couple of recent DB2-related articles/columns that I've had published. You can always keep up-to-date on my writings by visiting my web site at http://www.craigsmullins.com/articles.htm.Any way, the following three articles might be of interest to DB2 for z/OS folks:Use Real Time Statistics to Automate Your Database Maintenance was published in the April/May 2008 issue of zJournal. This article examines Real Time Statistics (RTS) and the benefits that can be accrued by using RTS....
Thursday, 17 April 2008
Mainframe Executive, a new publication for CIOs and IT managers in enterprises with IBM mainframe systems, just published a list of 15 reasons to stay on, or move to, a mainframe. The list is a good one, covering reliability, availability, security, resource utilization, scalability, power consumption, staffing concerns, quality, and on and on.Here is the list for those not inclined to click on the link:1. Lowest outage costs from highest platform reliability, availability, and serviceability.2. Lowest security breach risks/costs via most secure...
Thursday, 10 April 2008
Table expressions are frequently overlooked as a potential solution for resolving problems using only SQL. Table expressions can be used to force the optimizer to choose a specific processing order.For example, consider the following query:SELECT D.DEPTNO, MIN(D.DEPTNAME) AS DEPT_NAME, MIN(D.LOCATION) AS DEPT_LOCATION, SUM(E.SALARY) AS TOTAL_SALARYFROM DEPT D, EMP EWHERE D.DEPTNO = E.WORKDEPTAND E.BONUS BETWEEN 0.00 AND 1000.00GROUP BY D.DEPTNO;In this query, the detail rows that qualify from each table are joined...
Thursday, 27 March 2008
If you are a stored procedure developer, or a DBA who manages a system with stored procedures - - and you are running DB2 9 for z/OS - - there is an updated RedBook you should download immediately. It is titled DB2 9 for z/OS Stored Procedures: Through the CALL and Beyond. You may have the previous edition, DB2 for z/OS Stored Procedures: Through the CALL and Beyond (SG24-7083)...This new edition of an all-time favorite RedBook is newly updated to show the changes that have happened to DB2 stored procedures and related tools from V8 to V9. It offers...
Wednesday, 19 March 2008
I learned of some good news today. Evidently my DB2 book, DB2 Developer’s Guide, recently won the favorite book poll conducted by IBM Database Magazine (formerly DB2 Magazine) a couple of months ago… and it won by a substantial margin.Thanks to everyone who voted for my book… I appreciate your suppo...
Tuesday, 18 March 2008
Pearson and IBM Press have just published a new eBook on IBM database technology that is available for free download. Just follow this link, provide your e-mail, and they’ll direct you to a PDF containing sample chapters from six recently published books.The information in the eBook comes from the following books:Understanding DB2: Learning Visually With Examples, Second Edition by Chong, Wang, Dang, and Snow - Chapter 2: DB2 at a Glance: The Big PictureDB2 9 for Linux, UNIX, and Windows, Sixth Edition by Baklarz & Zikopoulos - Chapter 8: pureXML...
Monday, 3 March 2008
Recently, I received the following question, which I will answer today on this blog posting.Question: Lets say I have a table A which has 500 columns. Out of those 500 columns only 5 columns have been defined as not nullable and the rest have been defined as NULLS allowed. And out of those 500 columns I have found that 300 columns are unused(empty) totally. My business allows me to remove those 300 columns. My doubt is if I remove those 300 empty columns will I save on DASD space occupied by DB2? Will empty columns occupy DASD space?Would be really...
Wednesday, 20 February 2008
I know that this blog is supposed to be primarily about DB2, but I like to sneak in mainframe-related topics from time to time. And I read a great article today in Computerworld that I want to share with you. The article, titled Confession of a COBOL Programmer, talks up the need for COBOL coders. Just like with other mainframe technologies, as the baby boomers retire there is an insufficient supply of newbies available to step in and continue the care and feeding of the COBOL legacy.I've written briefly about COBOL before, in my Data Management...
Tuesday, 5 February 2008
Most seasoned SQL programmers know that when you use host variables, DB2 may not always come up with the absolutely most optimal access path at bind time. Without knowing the actual values of the host variables the optimizer has to make some best guesses as to how best to satisfy the SQL request.Furthermore, we know that we can guide DB2 on how best to approach this situation using the REOPT parameter of the BIND command. Prior to DB2 V9, there were three options for REOPT:REOPT(NONE) – DB2 will not reoptimize SQL at run time.REOPT(ALWAYS) – DB2...
Friday, 25 January 2008
Are you making plans to migrate to a new version of DB2? Do you know what impact the access changes for dynamic SQL will have on performance? When migrating to a new DB2 version, access path changes for dynamic SQL are unpredictable – as is the impact those changes will have on application performance. Learn how you can use Bind ImpactExpert to eliminate the unwanted surprises in version migration by performing a “precheck” on dynamic SQL access path changes.This webinar will be presented by myself (Craig Mullins) and Joe Brockert, Sr. Software...
Wednesday, 16 January 2008
I get questions e-mailed to me all the time. Although I try to read and answer them all, sometimes I don't. I hope those whom I've ignored over the years will forgive me, but I can't always answer everything (not enough time/energy) and sometimes things get lost or drop through the cracks.Anyway, at times I will take a question I get and blog about it in Q+A format. Today is one of those days!The question was: I want to perform a retry on an INSERT under DB2 Z/OS when I get a deadlock/timeout. -911 causes a rollback automatically. Is there a ZPARM...
I have been blog tagged by Willie Favero. Don't worry, its not as painful as it sounds!Basically, blog-tagging is a game, of sorts, that has been crawling its way through the blogosphere for awhile now. The way it works, when you are tagged by another blogger, you have to write a blog posting about yourself, with 8 things that others might not know. . . and then tag 8 other bloggers.So here goes:I am an avid music fan. At last count, I have 5,281 CDs and albums (yes, I still have records). I know exactly how many I have because, geek that I am,...
Tuesday, 15 January 2008
While researching some items on the web I ran across a couple of interesting mainframe-related sites that I'd like to share with you.First up, on The History of Computing Project's site, is this entertaining and informative timeline of mainframe history. The timeline starts in 1939 with the creation of the Atanasoff-Berry Computer at Iowa State. If you are looking for historical events in the life of the mainframe, then this is a good place to start. It contains links to information about, and pictures of, some early mainframes including the ENIAC...
Wednesday, 9 January 2008
With today’s posting we return to our examination of the new features of DB2 9 for z/OS. With V9, DB2 storage groups can be better integrated with SMS storage classes.Prior to DB2 9, you could only spcify SMS storage classes, data classes, and management classes when using explicit IDCAMS defines. You could use those SMS specifications with your SMS ACS routings, but ACS routines filter on data set names, so those routines could become large and unwieldy if you defined multiple different combinations for different data sets.The improvement in DB2...
Thursday, 3 January 2008
Just a quick post today to point you over to my Data Management Today blog. I use this blog to talk about data management issues that are not specific to DB2, whereas this blog focuses almost exclusively on DB2 (and mainframe) topics.But two recent posts at my other blog may be of interest to readers of my DB2 Portal blog. They deal with the topics of employability and pay -- two topics that are near and dear to the heart of IT and database professionals.Here are links to those posts:DBA Salary Update - a look at a couple of recent salary surveysDatabase...
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