Information integration: Aggregation
Problem: Data is not in exactly the form the user needs (monthly, not annually; actual values, not averaged)
Solution: Attempt to provide unified view of data of various granularities:
- time period
- geographical region
- product
- …
Example over BLS data:
- View: monthly data available for all geographical regions
- Query: monthly prices for LA in 1979
- Answer: yearly price for LA in 1979
Luis Gravano, Asst Prof, Columbia
Anurag Singla, GRA, Columbia