As with the other entries in my DB2 Basics series, this entry does not cover everything about triggers. Instead, I’m covering the basics and a few important points. DB2 triggers are sometimes over-used and over-complicated. Basically, triggers are actions(SQL) that…
Have you ever had to alter foreign keys in a way not supported by mere alteration? Dropping and re-creating all of them can be quite a chore, but a little SQL can make it easier. In this post, I’m sharing…
What is a table scan? DB2 has a number of ways of accessing the data it needs, but the most basic one – the one that will always work to get what it needs – is the table scan. A…
I’m happy to announce that I’m not just a blogger, I’m now a published author. My article “Mining your package cache for problem SQL in DB2 for Linux, UNIX, and Windows” is published today on the developerWorks site. It is…
(For Part 1 of this series, please click 10 Minute Triage: Assessing Problems Quickly, Part 1). One of my favorite commercials is from a motor oil company. The scene begins with a man who is sleeping soundly. His slumber ends…
To eliminate any confusion – I am not Ember. Ember is a little shorter, with a big smile, and glasses. I was lucky enough to meet her through a mutual friend at the IDUG 2012 Conference in Denver just a…
I read an article from Craig Mullins on “Working with variable data“. The rest of this post is going to assume you’ve read it, so click through and then come back. I’ve seen performance issues caused by VARCHAR before, and…
Edit 2019-04-02: corrected typo in the explanation of the -tbspname option. Also, a colleague notes that a 16K page size table space also works for this. db2caem is a tool in 9.7 that reports actual row counts in your explain…
So the basics of analyzing SQL on db2 are in my post on Analyzing SQL. I wanted to go a bit beyond the basics. First, you have to be able to read an explain plan. A couple of resources on…
The keyword in the title of this post is “basics”. I spend some time training SQL Server or Oracle DBAs on DB2, and so this is the answer on the most basic level to how to identify indexes to add.…
So I thought I’d do a short series on analyzing SQL. I want to focus on some of the techniques I use, so not necessarily everything you could know about it, but some basics on one way to do it. I’m going…
Many DBAs have their own methods and approaches in this area, but there are some basic sources and methods that I use. I’ll cover at least the basics of SQL analysis in one or more future posts Get SQL from…
