From Oracle FAQ
A bottleneck is the slowest operation in a set of operations. It is important to identify the bottleneck in computer systems to know what needs to be tuned to provide better performance and scalability.
- The I/O system may become a bottleneck on a large database system;
- If a database used more memory than what's available, paging and swapping will become a bottleneck;
- In a RAC system the interconnect may be overloaded (cannot handle all data transfers).
 Also see
|Glossary of Terms|