PostgreSQL supports ARRAY type, so I will use this.

https://docs.sqlalchemy.org/en/14/dialects/postgresql.html#sqlalchemy.dialects.postgresql.ARRAY

For flux columns in the targetDB, do we need the three kind of flux defined in the datamodel, (1) fiber_flux, (2) psf_flux, and (3) total_flux?

(1) Fiber flux need a seeing correction, but at Phase 2 and during the designing process, seeing cannot be known.

(2) PSF flux also need a PSF shape for extended source.

(3) Total flux can be submitted at Phase 2, but it may not be useful for objects which extends much larger than the fiber diameter. In this case, fiber flux would be more appropriate.

I can make these three, but if you have any suggestions, please let me know.

Related question: do we also need to make magnitude columns or just fluxes in nJy are fine?

Just a note:

To host an arbitrary photometric data points, there are ARRAY and JSON/JSONB types available in PostgreSQL. At this point, which type should be used in what kind of photometry depends on the demand from the data processing.

There could be 4 possibilities at this moment:

(1) just list each filter as a column, e.g., total_flux_g_hsc, total_flux_g_gaia, etc.

(2) use ARRAY type with a list of filters as another column.

(3) use JSON/JSONB type with filter info in each json entry.

(4) no photometry info in the targetdb (i.e., not be used in the data processing).