Designing and Mining Multi-Terabyte Astronomy Archives: The Sloan Digital Sky Survey

The next-generation astronomy digital archives will cover most of the universe at fine resolution in many wavelengths, from X-rays to ultraviolet, optical, and infrared. The archives will be stored at diverse geographical locations. One of the first of these projects, the Sloan Digital Sky Survey (SDSS) will create a 5-wavelength catalog over 10,000 square degrees of the sky (see http://www.sdss.org/). The 200 million objects in the multi-terabyte database will have mostly numerical attributes, defining a space of 100+ dimensions. Points in this space have highly correlated distributions. The archive will enable astronomers to explore the data interactively. Data access will be aided by a multidimensional spatial index and other indices. The data will be partitioned in many ways. Small tag objects consisting of the most popular attributes speed up frequent searches. Splitting the data among multiple servers enables parallel, scalable I/O and applies parallel processing to the data. Ha..