Jerome Kelleher

Sounds good. Any site with all missing data should be ignored I think, as a guiding principle.

I don't see why not, but there would probably be some semi complex plumbing involved. It's only used in the SampleData, I guess? Or are we using it for storing...

It would be nice to do, but it's not a priority. LMDB has served us well apart from a few install headaches.

I don't think the issue is backwards compatibility, more that we're still using lmbd for the current version of AncestorData. Do I understand this correctly @benjeffery?

I think we have enough to do for now, let's leave it as it is.

It's not clear when or if we'll move to Zarr v3 so this isn't going to change much. Easy enough to make a store anyway.

It's not trivial for the reasons you outline. Zero mutation sites is easy to do though, and we use that somewhere else

We're going to need something like this for testing anyway - even better if it was just an in-memory store.

We should also link to [sgkit's pedigree methods](https://pystatgen.github.io/sgkit/latest/examples/relatedness_tutorial.html) for a compatible way of doing more calculations. We would want a conversion function somewhere, but I'm not sure where that would...

I guess another possibility would be to provide an input CSV file (or Zarr) which is formatted with ``position, ancestral_allele, variant_age`` etc, which then populates the arrays appropriately.