ACM Queue - A Call to Arms - Long anticipated, the arrival of radically restructured database architectures is now finally at hand.: "We live in a time of extreme change, much of it precipitated by an avalanche of information that otherwise threatens to swallow us whole. Under the mounting onslaught, our traditional relational database constructs - always cumbersome at best - are now clearly at risk of collapsing altogether.
In fact, rarely do you find a DBMS anymore that doesn't make provisions for online analytic processing. Decision trees, Bayes nets, clustering, and time-series analysis have also become part of the standard package, with allowances for additional algorithms yet to come. Also, text, temporal, and spatial data access methods have been added - along with associated probabilistic logic, since a growing number of applications call for approximated results. Column stores, which store data column-wise rather than record-wise, have enjoyed a rebirth, mostly to accommodate sparse tables, as well as to optimize bandwidth.
Is it any wonder classic relational database architectures are slowly sagging to their knees?
But wait - there's more! A growing number of application developers believe XML and XQuery should be treated as our primary data structure and access pattern, respectively. At minimum, database systems will need to accommodate that perspective. Also, as external data increasingly arrives as streams to be compared with historical data, stream-processing operators are of necessity being added. Publish/subscribe systems contribute further to the challenge by inverting the traditional data/query ratios, requiring that incoming data be compared against millions of queries instead of queries being used to search through millions of records. Meanwhile, disk and memory capacities are growing growing significantly faster than corresponding capabilities for reducing latency and ensuring ample bandwidth. Accordingly, the modern database system increasingly depends on massive main memory and sequential disk access."
Another classic ACM Queue article -- the future of DBMS, by Jim Gray