Lists of Proximity Queries - the ProxList Server

The ability to submit multiple proximity queries together is currently not integrated within the sdssQT functionality, but is available for now separately via the ProxList server site. The procedure to submit an arbitrarily long list of proximity queries is as follows:

1.

Prepare your data input file (.dat extension usually) containing the list of RA and DEC coordinates for the locations where you want to do the proximity searches. The ProxList facility only requires a space-separated tabular format, and the actual coordinates may be in any columns you choose. You can specify the coordinate columns when you set up your ProxList query.

2.

Choose New Connection from the Connect menu in the sdssQT main window, and from the server menu at the bottom of the login window, choose ProxList. Log in as you would to any other server site, using your SDSS username and password.

3.

Once the ProxList server window comes up, load the match.sxql query from the query examples. Modify the SELECT and FROM clauses if necessary, to choose which attributes you want returned and if you want to run on some other tag class (other than Primary).

4.

Next, from the Tools menu, select Match data file .... This will bring up the file selection dialog, and you can choose the file by going to the appropriate directory and double-clicking on the file (remember that by default only .sxql extension files show up, so you may have to change the filter), or type in the pathname manually and press Load.

5.

This will bring up the ``Match File Parameters'' window. This is where you specify which column in your data file is which, and also the coordinate system you want to use (e.g. J2000) and the search radius in arcmin. The last field allows you to also specify the format of the output by selecting columns from the input file that you want included as ``extra columns'' in your output file. Note that columns in the data file are numbered from 0, not 1, so that column 1 refers to the second column, column 2 to the third column, etc.

6.

After you click OK in the match parameters window, you will see a ``comment'' line being added in the WHERE portion of your query that looks like:
#MATCHLIST /home/machine/me/mylist.dat J2000 1 2 0.1 0 1 2 3

7.

Now you can submit the query using the Launch button. Note that for ProxList queries, there is no syntax check or cost prediction, so the syntax check button does not do anything.

The output will be sent to the output file that you had selected, and also the preview window if your preview option is on. The progress bar will repeatedly go from 0 to 100% as each proximity query in the list executes in turn. Using the ProxList facility is awkward at best, but this is a temporary solution to the proximity list problem, and we will incorporate a permanent way to do this in an upcoming release of the SDSS Science Archive.