What would a sane API to use select_related look like ?

[stuaxo]

select_related, fails when you have different foreign keys on different parent classes.

I made a workaround, where the query is split up by type id, then for each of those select_related can be called -
https://gist.github.com/stuaxo/1e5f272d84e68eceaddafa0c7f9d37ae

For the data I'm using, I saw about a 3x speed up.

I wonder what the sane API for a django polymorphic select_related would look like ?

For the code, above we have a special field, "copyable_fields", and I choose things, based off that... that's probable not acceptable here, I guess if it was it might look like this (using the field name from my project above)

.polymorphic_select_related(fields_list="copyable_fields")

A slightly cumbersome alternative might be to pass in the list of fields to select_related, for each type

.polymorphic_select_related({Class1: ["field1", "field2"], Class2: ["field2", "field3"]})

This second one may not be as bad as it seems, as it could probably be done dynamically, I could even reproduce what I'm doing on my current project:

.polymorphic_select_related(model: model.copyable_fields for model in TrackedModel.__subclassess__())

Any other ideas ?

[stuaxo]

Update: speed up wasn't consistent in the app I'm using, I think a better mechanism than re-sorting everything at the end, than what I used in the gist might help.