2dFGRS Final Release Database
Notes and Hints


  • Queries typically take a few minutes to execute. The options "email URL of compressed text file" or "email URL of compressed FITS archive" run in the background.

  • The mSQL database is shutdown everyday around 06:30 local time while the scratch area is cleared. Queries running at this time will die, and results from earlier queries will be deleted.

  • Having data returned as an HTML table is really only suitable for queries returning relatively small numbers of database entries, especially where you wish to view the images and spectra. Large queries are best returned as a compressed text files. If you wish to view large numbers of images or spectra you should break your queries down into limited ranges of serial numbers.

  • Using the ORDER BY construction to sort the returned entries is not recommended for large queries, for which it is better to sort the returned text file off-line.

  • The various parameters kept as real numbers in the database are held with differing precisions. For example, the fields with upper-case names were written using Fortran free-format, which causes the precision to vary with the value of the number; the fields with lower-case names were written using a fixed format.


Matthew Colless, colless@mso.anu.edu.au,