| | You learned in A Vision for the Agile Data Method that agile methodologies such as eXtreme Programming (XP) (Beck 2000) and DSDM (Stapleton 2003) take an iterative and incremental approach to software development. Application developers on XP and DSDM projects typically forsake big design up front (BDUF) approaches in favor of emergent approaches where the design of a system evolves throughout the life of the project. On an agile development project the final design often isn't known until the application is ready to be released. This is a very different way to work for many experienced IT professionals to work. The implication is that the traditional approach of creating a (nearly) complete set of logical and physical data models up front isn't going to work. The main advantage of the traditional approach is that it makes the job of the process database administrator (DBA) much easier ?€“ the data schema is put into place early and that's what people use. However there are several disadvantages. First, it requires the designers to get it right early, forcing you to identify most requirements even earlier in the project, and therefore forcing your project team into taking a serial approach to development. Second, it doesn't support change easily. As your project progresses your project stakeholders understanding of what they need will evolve, motivating them to evolve their requirements. The business environment will also change during your project, once again motivating your stakeholders to evolve their requirements. In short the traditional way of working simply doesn't work well in an agile environment. If Agile DBAs are going to work on and support project teams that are following agile methodologies they need to find techniques that support working iteratively and incrementally. My experience is that one critical technique is database refactoring. Table of Contents 1. |
