jointcal isn't doing anything different from what meas_mosaic did in this regard. Replacing Calib with PhotoCalib is also independent of that (though I hope to tackle that soon).

I suppose that's fair.  I guess I had just envisioned Calib->PhotoCalib happening at the same time.

And now that I look into it, what exactly is an ExposureCatalog? The header file isn't very instructive.

ExposureRecord is basically a version of ExposureInfo that you can make a catalog out of.  We use them extensively in coadds to be able to store metadata about what into the coadd, including some things that are necessary for coadd functionality (like CoaddPsf).  And like any other kind of record, you can add other fields to them, too.  There's a sad tale of why ExposureRecord and ExposureInfo can't easily be unified that I think involves BBox ownership, but I forget the details.

There's a sad tale of why ExposureRecord and ExposureInfo can't easily be unified that I think involves BBox ownership, but I forget the details.

So, DM-7565 then?

That's at least some of it; might be all of it.

Done as part of DM-10156.

Now that this is done, Eli Rykoff: you and I should talk about better ways to persist PhotoCalibs from jointcal/fgcm runs to save a bundle of disk space.