Ah, thanks for clarifying, apologies for my misunderstanding.
You’re right that the entire books+authors query would have to be re-run in a single transaction to get internal consistency. This query would be for all intents and purposes equivalent to a select+join, as far as I can tell, with some watches thrown in.
def my_query(tenant) do
Repo.transactional(tenant, fn ->
[authors, books] = Repo.await([
Repo.async_all(Author),
Repo.async_all(Book)
])
aw = SchemaMetadata.watch_changes(Repo, Author)
bw = SchemaMetadata.watch_changes(Repo, Book)
{authors, aw, books, bw}
end)
end
Then more code to handle resolving the watch and run my_query(tenant) again.
EctoFDB.Sync’s functions don’t currently help in this case. The API hides the transaction behind a nice simple function call. And it promises to create all the correct watches for you, but only for certain query types.
However, I see no reason why the approach itself couldn’t be used with a little extra work from the developer.
Thanks for bringing this up, it’s important for me to recognize and call out the limitations of the sync features.
There is one thought in the back of my mind while I was writing this post: I suppose anytime one tries to create query conventions on these transactions, one risks creating a new query language (please no).
