Abstract
Today's enterprise databases are large and complex, often relating hundreds of entities. Enabling ordinary users to query such databases and derive value from them has been of great interest in database research. Today, keyword search over relational databases allows users to find pieces of information without having to write complicated SQL queries. However, in order to compute even simple aggregates, a user is required to write a SQL statement and can no longer use simple keywords. This not only requires the ordinary user to learn SQL, but also to learn the schema of the complex database in detail in order to correctly construct the required query. This greatly limits the options of the user who wishes to examine a database in more depth. As a solution to this problem, we propose a framework called SQAK1 (SQL Aggregates using Keywords) that enables users to pose aggregate queries using simple keywords with little or no knowledge of the schema. SQAK provides a novel and exciting way to trade-off some of the expressive power of SQL in exchange for the ability to express a large class of aggregate queries using simple keywords. SQAK accomplishes this by taking advantage of the data in the database and the schema (tables, attributes, keys, and referential constraints). SQAK does not require any changes to the database engine and can be used with any existing database. We demonstrate using several experiments that SQAK is effective and can be an enormously powerful tool for ordinary users. Copyright 2008 ACM.