This paper from Google talks extensively about the usage of BigTable and Megastore, the data model, query processing, and transaction handling in the implementation of Google Fusion Tables.
Google Fusion Tables is a cloud-based service for data management and integration. Fusion Tables enables users to upload tabular data files (spreadsheets, CSV, KML), currently of up to 100MB. The system provides several ways of visualizing the data (e.g., charts, maps, and timelines) and the ability to filter and aggregate the data. It supports the integration of data from multiple sources by performing joins across tables that may belong to different users. […] This paper describes the inner workings of Fusion Tables, including the storage of data in the system and the tight integration with the Google Maps infrastructure.
Download the paper or read it after the break.
You can get the PDF from here .
Original title and link: Paper: Google Fusion Tables: Data Management, Integration and Collaboration in the Cloud ( ©myNoSQL)