Author: Ember Crooks

5

Explain Part 3 – Visual Explain

Please start with the first two articles in this series: Explain Part 1 – Explain and the DB2 Optimizer Explain Part 2 – Command Line Explain Plans Using db2exfmt Explain is one of the few areas where I can see the argument for using a GUI. There are some neat features in Visual Explain and I haven’t seen many bugs...

2

Happy Third Blogiversary to db2commerce.com!

Wow, I have been blogging for a full three years now! I have only consistently blogged weekly for about 1.5 years. But what success blogging has brought me! I put a lot of effort into my blog. One of my favorite things in the world actually turns out to be writing a good blog post – it can wash away...

8

Explain Part 1 – Explain and the DB2 Optimizer

Generating an Explain Plan is easy… Properly reading an Explain Plan is harder… Taking appropriate action is harder still. When I started my career as a physical DBA with IBM Global Services, generating Explain Plans or even general analysis of SQL was not really a part of my job description. As I learned more about performance tuning and the limitiations...

4

When is ‘AUTOMATIC’ Not STMM?

Somewhere along the line, I associated ‘AUTOMATIC’ settings for parameters with DB2’s Self-Tuning Memory Manger (STMM). But the two are not associated. Sure, if STMM is set to ON, then some parameters set to AUTOMATIC will be tuned by the STMM, but many parameters can be set to automatic whether STMM is ON or not. What Parameters STMM can Change...

5

Check Out the New db2commerce.com Site Design!

You may have noticed that I have updated the site design for db2commerce.com. Check it out and let me know if you find any problems or have any suggestions. Web design is not my first line of work, but I’m pleased with how it came out. I went live with the new design late last week after some helpful input...

2

SQL Tip: COALESCE

I haven’t generally been known for my SQL tips. I can find my way around SQL decently enough, but for years, I didn’t do much of it. I’ve used it more and more as the years have gone by as I have moved out of a stictly physical/system DBA role and into a more mixed role where I interact and...

2

WebSphere Commerce Instance Creation Creates Database as Wrong User

This post is specific to WebSphere Commerce. We’ve reported this issue to IBM, but since we’ve run into it several times across more than a year, and in multiple different Fix Packs of Commerce, I thought I’d share it in case someone else runs into it. The main way it manifests initially is like this: /configureWorkspaces.xml:245: com.ibm.db2.jcc.am.SqlSyntaxErrorException: DB2 SQL Error:...

3

What to do with a Character you Cannot Query

This post comes out of one of the more challenging technical problems I have encountered recently. Problem Description An international client went live recently. We did the work of building their new WebSphere Commerce 7 website, and go-live involved loading some data from their old site. I’m not sure exactly how that load was done, but I suspect massload (a...

0

IDUG NA 2013 Pictures

Ok, this is the last post focused on IDUG NA 2013. I posted something deeply technical yesterday, didn’t I? I wanted to share some pictures from the conference. I snaged these from various Twitter and Facebook posts, so thanks everyone who took pictures. Scott Hayes, Dan Luksetich, Kurt Struyf, and Me (taken by Kelly Fitzgerald) Me with JB, Rebecca Bond,...