SPARK: A Keyword Search Engine on Relational Databases

Relational database is the most widely adopted and mature technology for information storage. As many services on the Web (e.g., blog and wiki sites) and advanced applications (e.g., customer relationship management systems and content management systems) are built on RDBMSs, increasing amount of text data is now stored in relational databases, accompanied by increasing demands of retrieving relevant information by free-style keyword search.