RSCT APAR Affecting TSAMP

Some of my clients, instead of engaging me for day-to-day support, engage me for expert assistance only when it all really hits the fan. This issue occurred for one of those clients, who had other support performing the HADR failovers while the Linux kernel was upgraded. The version of RedHat did not change, but the kernel did.

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Db2 Basics: Error Messages

When I do work in other domains – even something as connected as scripting – I find the error messages confusing and unhelpful. Most of the time, this is mostly because I don’t know much about the language or the the area. I’d like to think that my opinion that Db2 error messages are really quite helpful and useful is unbiased, but having built a career on focusing on IBM Db2, I’m sure I am biased.

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Query Performance Analysis

Some of the more complicated work a DBA does is often analyzing a query. Whether it is proactive or in response to a performance problem, there are so many factors that go into query performance. Even when looking at a query that has a performance problem, there is only occasionally a single, obvious cause for all of the problems.

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Comparing Two Db2 Systems

Sometimes configuration needs to be kept in sync between two or more Db2 systems. There are a variety of reasons – sometimes this is for keeping two HADR servers in sync, and other times it may be for keeping a dev, QA, or Staging system in sync with production. In any case, having an idea of what needs to be in sync and what doesn’t can be complicated. The focus here is at the system level. This post does not dig into comparison of logical objects in the database such as tables and indexes.

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Nothing Changed! A DB2 LUW Performance Investigation

I think that one of my least favorite phrases is “Nothing else changed!” More common than a performance problem that simply slowly creeps up with performance getting worse and worse over time is the sudden performance problem. Many times, sudden database performance problems can be mapped back to a specific change at some level.

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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 upgrade).

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