13.1 Introduction

In the previous chapter we discussed backup and recovery. We discussed why backup was one of the critical parts of any Information Technology implementation. Hardware redundancy provides availability to the computer system by making hardware components available as backup when the main components fail. In the case of data that is stored on the various hardware devices, such as operating system and database files, copies of these devices are required to be maintained at remote locations. When the main device fails, the data could be restored from these remote copies. We discussed various backup methods, hot, cold, and backups using RMAN. RMAN provides a more real-time backup method where backups could be performed while the database is operational without requiring any part of the database to be down or unusable.

We also looked at the various scenarios when a database, instance, node, and memory structures could fail, how during these various failure situations the various recovery methods are applied, and how Oracle performs the recovery.

Backup is important; equally important is the performance of the database system because there would no requirement for a backup system if the current database system is not usable because of its poor perform ance. User satisfaction is critical to the success of the enterprise system. On slowly performing systems, user satisfaction is seldom achievable.

Performance tuning is a very wide subject. There are several approaches to tuning a system. Tuning could be approached artistically like a violinist who tightens the strings to...