A requirement of any mission-critical database- driven applications is to have the information available and to be able to process it as fast as possible. To fulfill this requirement, the database should have a high-availability feature as well as the optimal workload performance. With an assessment of the Oracle s high-availability database, in terms of the main architectural components and their impact on performance, we have developed a solution for the efficient and resource- effective tuning of Oracle databases. Our solution consists of a tuning strategy, implemented with a custom developed tool, enabling proactive and reactive database tuning. With the proposed tuning strategy and a set of SQL query scripts implemented in custom developed Java tool, we have demonstrated that our tool can be used for the measurement of the main Oracle database component s workload performance and object optimization, in order to achieve and maintain the optimal database workload performance.