is the order that meltano operates “expectable”? Does it extract data in the order found when doing meltano select?

Short answer I believe is no (But I"ll offer some ways to do this) It all depends on the

tap

Meltano's

select

generates a

catalog.json

file (See https://hub.meltano.com/singer/spec#catalog-files ) the

tap

ingests that catalog.json file and then does with that as it pleases (Some may go in order, some may not, it depends) What that means is that you could select one stream at a time (Using something like https://docs.meltano.com/concepts/plugins#select_filter-extra , via env variables is one way) and then Meltano would select only one stream, and the tap would have to select only that one stream. That way you could load the data in the order you wanted at the cost of the overhead of writing your own select filters and running the tap multiple times

I think it was mostly understanding the progress a particular tap is making through a workflow. I think just looking at the select output gave me a rough order of things and i was able to tail the logs to see how it was going through and estimate how much was left. It was more for observability than a hard use case. Your links are very interesting to me though!!