Applications can require recoding. Moving data to a parallel architecture is work, although tools exist to help. You must train people for the environment. A key issue is figuring how to spread your data properly, which requires understanding the nature of the data and how it will be used. Given the increasing reliance of many organizations on data manipulation, a boom in parallel processing for data querying probably is on the way.
Applications tend to grow, and data tends to grow a lot faster than anticipated.
You need to plan for the future. Platforms A decision support database is oriented toward large-scale sorting and searching in large databases, usually those comprised of historical data. Queries typically involve full-table scans requiring minimal indexing. In this environment, speed is everything. All the major vendors of open systems databases strive to enhance the performance of their products as new processors and higher clock speeds appear on the market.