What is optimization and performance tuning and How does it work in practical projects. Explain with an example. | Teradata Interview Questions

Optimization is the technique of selecting the least expensive plan (fastest plan) for the query to fetch results.
Optimization is directly proportional to the availability of -
1. CPU resources
2. Systems resources - amps PEs etc.
Teradata performance tuning is a technique of improving the process in order for query to perform faster with the minimal use of CPU resources.