Information Content Inclusion Relation and its Use in Database Queries

A database stores data in order to provide the user with information. However, how a database may achieve this is not always clear. The main reason for this seems that we, who are in the database community, have not fully understood and therefore clearly defined the notion of “the information that data in a database carry”, in other words, “the information content of data”. As a result, databases’ capability is limited in terms of answering queries, especially, when users explore information beyond the scope of data stored in a database, the database normally cannot provide it. The underlying reason of the problem is that queries are answered based on a direct match between a query and data (up to aggregations of the data). We observe that this is because the information that data carry is seen as exactly the data per se. To tackle this problem, we propose the notion of information content inclusion relation, and show that it formulates the intuitive notion of the “information content of data” and then show how this notion may be used for the derivation of information from data in a database.