Review

I first heard about a hot west coast operator called ``Data Cube'' by Gray & Co in November 1995 at the CIKM'95 workshop in Baltimore. I immediately e-mailed Jim requesting the paper and got back the URL to his collection of papers at his new then job at Microsoft. I downloaded the paper and started reading the paper but, to my disappointment, the figures which, in this particular case are worth more than just a thousand words, had a big cross with some Microsoft mumbling underneath. I guess Jim was still in the process of mastering Microsoft software! Nevertheless, I was able to get the basic ideas before the New Orleans conference where I got to see those figures.

The Data Cube paper is to the area of OLAP and data warehousing the equivalent of what the 1970 Ted Codd's paper was for the relational databases. It formalized the concepts of multidimensional aggregate views and the hierarchies within them. It also set the first ideas on the complexity of the incremental algorithms for maintaining various aggregate functions. This paper tremendously influenced my research on the cubetree storage organization and its bulk update. In 1995, I was working on materialized views with aggregate and other functional abstractions in them. There was no better timing for this. Thanks Jim, Adam, Andrew and Hamid.