Joining tables via indices within nsc_dr1

Question

I would like to retrieve rows after doing a database join between the nsc_dr1.object and nsc_dr1.nsc_allwise tables.

Do any of the fields in the nsc_dr1.nsc_allwise table give the index of the corresponding object in the nsc_dr1.object table, or do I have to do a sphere match?

Thanks,

Answer 1

The nsc_dr1.nsc_allwise 'id' column us the nsc_dr1.object 'id' value, and likewise the 'coadd_id' and 'source_id' columns are the matched rows from AllWISE.  Each of these columns is indexed in both parents and the 'nsc_allwise' crossmatch table and so you could do a simply JOIN (depending on your query) on these values.  The index-value/row-number is not stored in the tables.

Comments

Thanks for the help.

Note that when accessing these tables in Topcat (v4.5-1) via http://datalab.noao.edu/tap, the  'id'  column of the nsc_dr1.object table is presented as a CHAR[1] whereas it should presumably be a CHAR[16].

Things became much clearer when I used the datalab query interface,
http://datalab.noao.edu/query.php?name=nsc_dr1.object

Thanks again.
Tom

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Thanks for pointing that out.  The column width is correct is database for nsc_dr1.object.id, however the 'tap_schema' tables that describe the tables for TAP clients such as TOPCAT only had this listed as a single char.  This has been fixed, you should see the full width now after reloading TOPCAT.