1. Power-Aware Databases
Yicheng Tu
Assistant Professor, CSE
Electricity bill – 2nd largest item in the total ownership costs in running a database system
Data centers consumes 0.5% of world’s energy
May increase to 2% by 2020
Power-aware computing has focused on hardware and OS
Now it is time for power-aware software applications
Applications are passive
Different ways (plans) to accomplish the same task
Choose a plan with low energy cost
Provide extra opportunities for saving energy by rescheduling and re-optimization

2. Power-Aware Databases
Database management systems Current DBMS: choose plan by one single criterion – processing time Consider energy as another criterion? Main challenges: How to estimate the energy cost of plans? Optimal control? Query processing time is also important. Online decision making – which plan to choose?
Chosen Plan
For execution
Query
Query Interpreter
Plan Generator
Plans
Query Optimizer