SYSTEM FOR KEYWORD BASED SEARCHING OVER RELATIONAL DATABASES

Searching by keywords on a relational database is enabled by performing preprocessing operations to construct lookup tables at an interim level of granularity, such as column location. A keyword search is performed on the lookup tables rather than the database tables to determine database column locations of the keyword. Schema information about the database is used to link the column locations to form database subgraphs that span the keywords. Join tables are to generated based on the subgraphs consisting of columns containing the keywords. A query on the database is generated to join the tables and retrieve database rows that contain the keywords. The retrieved rows are ranked in order of relevance before being output. By preprocessing a relational database to form lookup tables, and initially searching the lookup tables to obtain a targeted subset of the database upon which SQL queries can be performed to collect data records, keyword searching on relational database is made efficient.