file0001569077358 0

Comparing dsmtop and db2top

dsmtop is a long-awaited refresh of the wildly popular db2top. Like db2top, dsmtop is a free tool, included with DB2. It is in the base DB2 install starting with 11.1, and can be installed on DB2 10.1 or 10.5. History of db2top As I personally recall, db2top first came out of IBM AlphaWorks. My understanding of IBM AlphaWorks is that...

red mask black box 2

Finding the Subnet Mask on AIX

This is something DB2 DBAs may need to do as a part of setting up TSAMP. Nearly every server I’ve done before has had a subnet mask of 255.255.255.0, but I ran into a server recently that wasn’t, and thought I would share how I figured out what it should be (alone, in the middle of the night, during an...

7

Reclaimable Table Spaces

In DB2 9.7, IBM changed the format of table spaces to be “reclaimable”. This has a ton of advantages, but conversion is ridiculously painful. Why Was the Format Changed? Previously, row addresses (referenced in indexes) were relative to the beginning of the table space. This has a number of implications, the main one being that if tables are moved within...

RFE_Subscribe_Roland 5

IBM’s DB2 RFE Program

RFE stands for “Request for Enhancement”. IBM has this program for a number of products, but until late 2016, the RFEs for DB2 on LUW were not publicly available to vote on. Now they are, and we’re seeing action on them. The Problem It can be frustrating to have an issue that IBM describes as “working as designed”. Sometimes these...

004 3

The Role of the DB2 DBA in Load/Performance Testing

I am consistently shocked and appalled at how few clients actually do load testing. Many pay it lip service, but few actually engage in real, meaningful performance and load testing. I understand that load testing of an application can be difficult and expensive. It is not something that every developer has as a part of their toolkit. But the most...

DSCF3217 1

The Role of a DB2 DBA and of the DB2 Consultant

This blog post was inspired by a DM on Twitter. A follower asked me for ideas on how to best interact with developers and how much expertise to give away. This is a big question with a vast array of correct answers. It is also a subject on which I have a lot of opinions that are wholly mine and...

9084e86df620f051cfdd4b4187924b21 2

Understanding Return Codes in the DB2 Diagnostic Log

I learned a nifty little trick while troubleshooting a connection issue, and thought I would share. It can be useful in getting information out of the db2 diagnostic log. DB2 Diagnostic Log The DB2 diagnostic log has a wealth of information. After over 15 years working with DB2, I still learn new things about how to read it every single...

Sandpit-0862 1

Building a Sandbox VM for DB2

There are plenty of things that I want to try in a sandbox VM before I let them anywhere near even a development environment. Even if I didn’t use it constantly for blogging, I would still need it for trying things to see how they work before advising clients. These instructions should never be used to build a development, test,...