Define the schema of prototype of targetDB

TargetDB is supposed to be a database hosting all targets for PFS (cf. opDB is for actually observed (or designed) targets, I believe).

I made an initial schema for targetDB which is based on the target and related tables in opDB sometime earlier. Although there are some parts which do not conform the datamodel, I would like to have your feedback to improve it (I know there are a lot of points to be discussed).

One noticeable feature is the introduction of the unique_object table. It is supposed to host unique objects on the sky and referred in the target table to handle duplication. My idea is to check duplication with objects already registered to the unique_object table by a cone search with a search radius of 1/2 to 1/3 of the fiber diameter. If no object is matched for an object, this object will be inserted in the unique_object table. I'm not sure whether this is the easiest way to handle duplication, so comments on this are very welcome.

Attached files (ver 2020-10-06 HST):

• schema_targetdb_tables.pdf : Information on columns in each table.
• schema_targetdb.pdf : Schema diagram of the current prototype.