Efficient Keyword Search on Structured and Semi-Structured Data from Relational Databases

Nowadays all Internet users use a search engine daily, performing a billion searches. The success of keyword search stems from what it does not require namely, a specialized query language or knowledge of the underlying structure of the data. Lack of standardization has resulted in contradictory results from different evaluations, and the copious discrepancies mix-up what advantages are proffered by different approaches. We also discuss applications that are built upon keyword search, such as keyword based database selection, query generation, and analytical processing. Finally we identify the challenges and opportunities of future research to advance the field. It presents the most general empirical routine appraisal of relational keyword search techniques to appear to date in the literature. Our results indicate that many existing search techniques do not provide adequate performance for realistic recovery tasks. And also explore the relationship between execution time and factors varied in previous evaluations; our analysis indicates that most of these factors have moderately little impact on performance.