Recoverability Trumps Performance By Craig Mullins Many DBAs reading this article will look at the title and immediately think I’m wrong… at least initially. They’ll claim that managing performance is the most important thing they do, but they are confusing frequency with importance. Yes, DBAs confront performance issues more often than they build backup plans – and they better be...
Author: Craig Mullins
DB2 SQL: Stages 3 and 4
DB2 SQL: Stages 3 and 4 By Craig S. Mullins All good DB2 developers and DBAs know about Stage 1 and Stage 2 predicates, right? But have you ever heard of Stage 3 and Stage 4 predicates? Well, you’re about to! First of all, let’s do a quick review to catch those readers who don’t know what Stage 1 and...
New Year’s Resolutions for DBAs
New Year’s Resolutions for DBAs By Craig Mullins At the beginning over every year many of us take the time to cobble together some resolutions for the coming year. We plan to lose weight, save money, stop smoking, and so on. Usually, it doesn’t take long before we’ve abandoned these resolutions. Perhaps we’d be wiser to make some business related...
Data Administration versus Database Administration
Data Administration versus Database Administration By Craig S. Mullins What is data administration (DA) and what does it have to do with database administration (DBA)? Well, in this day and age, the term “data administration” is not used nearly as commonly as it was just a few years ago. Instead, we hear terms like data governance or data architecture. But...
Database Design: From Logical to Physical
Database Design: From Logical to Physical By Craig S. Mullins A proper database design cannot be thrown together quickly by novices. What is required is a practiced and formal approach to gathering data requirements and modeling data. This modeling effort requires a formal approach to the discovery and identification of entities and data elements. Data normalization is a big part...
Reading Things That Aren’t There… and Missing Things That Are!
Reading Things That Aren’t There… and Missing Things That Are! By Craig Mullins You can shoot yourself in the foot using DB2 if you are not careful. There are options that you can specify that may cause you to read data that is not really in the database. And, alternately, you can set things up so that you miss reading...
Materialized Query Tables…and the Death of Denormalization?
Materialized Query Tables…and the Death of Denormalization? By Craig S. Mullins Materialized Query Tables, or MQTs, are provided by many relational database systems as a means of speeding up access to static data. You also may know them as Automatic Summary Tables, or ASTs, but regardless of the name, the functionality is basically the same. Though not exclusively for data...
The Ever-Changing Role of the DBA
The Ever-Changing Role of the DBA by Craig S. Mullins Defining the job of DBA is getting to be increasingly difficult. Oh, most people know the rudimentary aspects of the job, namely keeping your organization’s databases and applications running up to par. The DBA has to be the resident DBMS expert (whether that is DB2, Oracle or SQL Server, or...
Denormalization Techniques for Relational Databases
Denormalization Techniques for Relational Databases By Craig S. Mullins Speeding the retrieval of data from relational tables is a frequent requirement for DBAs and performance analysts. One way to accomplish this is to denormalize the tables. The opposite of normalization, denormalization is the process of putting one fact in many places. This speeds data retrieval at the expense of data...
SELECT from DELETE, UPDATE, and MERGE
SELECT from DELETE, UPDATE, and MERGE By Craig S. Mullins A nice and relatively new SQL feature of DB2 for z/OS offers the ability to SELECT from DELETE, UPDATE, and MERGE statements. This was introduced in Version 9 and is similar to the SELECT from INSERT feature that was introduced with DB2 V8. So, before looking at the new V9...