Build your own SkyNode!

SkyQuery is an excellent VO prototype application that marries Web Services technology with emerging VO standards to enable dynamic cross-matching queries between different VO-enabled archives. The archive data is stored in databases that are published online as SkyNodes. As the available data from Sky Surveys and new digital archives rapidly multiplies every year, more than 80 percent of the data will exist outside of large data centers at any given moment, making it very important to have dynamic cross-identification tools like SkyQuery. Loading an entire survey like 2MASS or SDSS into a database involves making decisions about issues like data formats and indices for tables. We describe the process of loading such a large amount of data into a relational DBMS (SQL Server) and generating a sky index using the Hierarchical Triangular Mesh (HTM), which provides a really fast way to find objects. This can be easily done even for a large survey like the 2MASS All-Sky Data Release (150GB uncompressed, 471M objects) in as little as 2 days including the required computation time for HTM.