I frequently get e-mails with DB2 questions and I plan to start posting answers to some of the more common ones up here.One issue that comes up a lot is dealing with locking issues. Usually it is posed by someone who is experiencing timeouts in an online environment and they want to know how to minimize them. Here is some guidance.When you experience a timeout, it means that another process holds a lock on the data that you are trying to modify. So, it stands to reason that you should try to minimize the duration of locks that are being held in...
Monday, 19 December 2005
Monday, 12 December 2005
Help Defining DB2's Business Value
Posted on 07:02 by Unknown
Every now and then those of us working on mainframe platforms are confronted by folks who are looking to eliminate mainframes. This can happen for any number of reasons. Maybe the confronter view mainframes as “old technology,” or “mainframes are too costly,” or some other trumped up charge. Too often, however, we respond to such claims emotionally instead of with reason and knowledge.Fortunately, IBM has come up with some help for those of us working with DB2 for z/OS. IBM has published – and made available for free download – a great little manual...
Tuesday, 6 December 2005
The Aging Mainframer
Posted on 15:20 by Unknown
A continuing, lingering perception that the mainframe is dead continues on in some parts of the IT industry. It seems that we constantly hear that big IT shops are getting rid of their mainframes. But rarely do we ever hear about it after the fact. No, it is usually reported right when someone thinks that it is a good idea.Now don't get me wrong. I'm sure there are some shops that have removed their mainframe. But I'm also sure that there are many more that thought about it but couldn't do it -- as well as those who wouldn't even consider it.A...
Tuesday, 29 November 2005
Cross Platform Help
Posted on 12:35 by Unknown
As regular readers of this blog know, this space is devoted to DB2 for z/OS – that’s the mainframe for those of you just visiting. I’d like to take a moment here, though, to point out some interesting posts for cross-platform DB2 DBAs.Chris Eaton, Senior Product Manager for DB2 Universal Database at IBM, writes a blog for ITtoolbox focusing on DB2 UDB for Linux, Unix, and Windows (LUW). If you use DB2 on that platform, be sure to read his blog regularly.So why am I mentioning this on a mainframe DB2 blog? Well, Chris has recently posted some very...
Tuesday, 22 November 2005
Mainframes Rock!
Posted on 12:16 by Unknown
It is good to see mainframes getting some positive press again. I'm talking about this November 17, 2005 article published in InfoWorld. It talks about a company that tried to get rid of its mainframe and replace it with first, Windows servers; and when that didn't work, Unix servers. When neither worked for them, they finally gave in and moved back to the reliable environment provided by mainframe computing.Basically, it boils down to this. There are some workloads that just are better off being served by mainframes. This is the parallel I like...
Monday, 21 November 2005
To REBIND or Not to REBIND, That is the Question
Posted on 13:11 by Unknown
There are two basic mindsets on when to REBIND your DB2 plans and packages. The first -- which I believe is the best approach -- is to REBIND regularly after running RUNSTATS. Using this approach you will ensure that your access paths have been formulated by the DB2 optimizer using the most up-to-date information available on your data. If you fail to REBIND your static SQL you are failing to give DB2 the chance to achieve the best performance it can for your applications.(Of course, this begs the question: "How frequently should I run RUNSTATS?"...
Friday, 11 November 2005
New DB2 DBA Portal from IBM
Posted on 07:20 by Unknown
Just a quick post to alert readers to a new portal from the IBM DeveloperWorks team. The portal is named DBA Central and it bills itself as offering resources for IBM Information Management database administrators.So, the portal won't be 100% mainframe content, but it should have some interesting nuggets of data for mainframe DB2 DB...
Thursday, 10 November 2005
DB2 Compression: z/OS versus LUW
Posted on 09:11 by Unknown
Space compression for non-mainframe DB2 is quite a bit different than it is for DB2 for z/OS. In mainframe DB2, specifying COMPRESS YES on the CREATE TABLESPACE statement will cause DB2 to implement Ziv-Lempel compression for the table space in question. Data is compressed upon entry to the database and decompressed when it is read.For DB2 UDB on Linux/Unix/Windows, when creating a table, you can use the optional VALUE COMPRESSION clause to specify that the table is using the space saving row format at the table level and possibly at the column...
Friday, 4 November 2005
No Black Boxes!
Posted on 21:35 by Unknown
I've written about this subject before, but I think it is important enough to merit another go-round. First of all, before I go any further, let's first define what I mean by a “black box.” If I plan to recommend that you prohibit them we better both understand what it is we are talking about proscribing.Simply put, a black box is a database access program that sits in between your application programs and DB2. It is designed so that all application programs call the black box for data instead of writing SQL statements that are embedded into a...
Friday, 28 October 2005
A Forced Tour of Duty
Posted on 06:34 by Unknown
Well, as promised, here is my first real post to my DB2portal blog. I want to use this post to rant a little bit about mainframes and their robust management environment.Mainframe developers are well aware of the security, scalability, and reliability of mainframe computer systems and applications. Unfortunately, though, the bulk of new programmers and IT personnel are not mainframe-literate. This should change. But maybe not for the reasons you are thinking.Yes, I am a mainframe bigot. I readily admit that. In my humble opinion there is no finer...
Thursday, 27 October 2005
Welcome to my DB2 Blog
Posted on 15:32 by Unknown
Hi everyone.This is just a short post to introduce my new blog here on DB2portal.com. I write a regular blog on DBMS, data, and database management over at dbazine.com - you can check it out at here if you'd like.This blog will be a little different than that one in that I will keep my comments focused on DB2 for z/OS and mainframe "stuff" only. Well, I might post something totally "off-topic" every now and then, too. Maybe if a news item touches a personal nerve - or I happen upon something too funny to not comment on.I'll try to post something...
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