Components of a Database Tuning Methodology:
1. Database analysis phase,
2. Logical design phase,
3. Physical design phase,
4. Database implementation phase,
5. Database testing phase, &
6. Database maintenance phase.

Implementing a Database-Tuning Plan:
1. Identify your performance tuning goals,
2. Identify your particular system’s characteristics,
3. Perform initial problem assessment while considering known problems and issues,
4. Perform problem investigation to identify the components that affect performance most,
5. Perform result analysis, for example, from gathered statistics,
6. Develop a solution proposal to identify changes to be made,
7. Carryout solution implementation, &
8. Perform proactive system monitoring to determine whether the problem identified has been met. If not, repeat steps 6 through 8.

Oracle recommends a Top-down approach (below) that emphasizes examining the highest performance payoff areas first, and leaving areas with the least performance impact for later inspection. By using this tuning approach or methodology, data and application related areas are examined first before any database tuning issues are considered, because 90 percent of all tuning issues are application related. And changes made in these areas can have a large impact on the remaining areas. For example, improvements in application design may necessitate changes in the areas of memory allocation and disk I/O (Johnson, 2002).

Oracle’s Top-down Tuning Methodology in order of Priority
1. Tune the Data Design
2. Tune the Application Design
3. Tune Memory Allocation
4. Tune I/O and Physical Structure
5. Tune Resource Contention
6. Tune the Underlying Platform(s).


References
Afyouni, A. H. (2004). Oracle 9i Performance Tuning: Optimizing Database Productivity. Thompson Course Tech.

Alapati, S. R. (2008). Expert Oracle Database 11g Administration. Apress.

Johnson, J. C. (2002). OCP: Oracle9i performance tuning study guide. Illustrated Edition. John Wiley and Sons.

Millsap, C. V. & Holt, J. (2003). Optimizing Oracle performance. O’Reilly.