It hardly needs reiterating that companies and other organisations are under increasing pressure to understand their customers, work ever more closely with their suppliers, evaluate their own performance, improve their competitive position, and generally take advantage of whatever business opportunities arise. Add to this the huge growth in information generated by the Internet as well as specialist technologies such as RFID (radio frequency identification) and event processing, plus the need to retain data for extended periods of time for compliance reasons, and it is not surprising that business intelligence and query systems in general are under increasing pressure. Worse, demands on this information are increasingly widespread and of a real-time nature.

Historically, all long term storage of data for query purposes has relied on data warehouses and data marts that have been traditionally supplied by vendors using conventional relational databases. However, for more than a decade a sub-genre of the relational database has been making inroads into the market, using a technology known as a column-based relational database (sometimes referred to as CBRD). While we will explain the differences between a conventional and a column-based approach in due course, for the moment just think of it as an ordinary relational database (using SQL and so forth) that inserts and reads columns of data instead of rows of data.

For much of the last decade the use of column-based approaches has been very much a niche activity. However, with eight vendors (that we are aware of) now active in the market, with approaching 1,500 customers (many of them Global 2000 companies) between them, we believe that it is time for columns to step out of the shadows to become a major force in the data warehouse and associated markets. Given that view, this paper will define what column-based relational databases do and how they do it, and where they have advantages (and disadvantages) compared to traditional approaches. This in turn will lead to a discussion of the sort of environments for which columns are best suited.