You can still only pull the data that you need using Meltano, but you select things on a "Stream" / "Attributes" level. For source DBs this means something like Table and Field level is as granular as you get.
Please let me (Meltano CEO) know how we could make that more obvious!
"ELT for the DataOps era
Meltano is open source, self-hosted, CLI-first, debuggable, and extensible."
That doesn't tell me what Meltano is.
I happen to recognise "ELT" as "Extract, load, transform" but I imagine a lot of people would have to look up the acronym.
I hadn't seen the term DataOps before, despite working in this area. DevOps for Data? But the definition of DevOps itself is still pretty vague!
I know how hard it is to explain what a product like this does - I'm definitely not there with my own https://datasette.io/ project yet - but what you've got right now could definitely do with some improvement.
Here's my attempt for Meltano, based on a very loose understanding of what it is:
"Meltano is an open-source tool for building automated pipelines for extracting and converting data. Pipelines are defined using version-controlled code, and the framework can be extended using plugins written in Python."
This really isn't very good, but it does fill in the questions that I had when I first visited https://meltano.com/
I was also confused as to what Meltano actually is or does, but everyone here seems to be so excited and genuinely happy for you and that made me super curious. It must have taken me several minutes of roaming around the website and docs before I finally figured it out though!
The main problem, I believe, is that there is too much copy that describes how the product will make its users feel etc. and far too little that tells us about its technical capabilities and its use cases. That notwithstanding, the copy is beautifully written and it has a very nice and smooth flow.
Being a developer myself and have seen/operated similar systems before made it not too bad to connect the dots. But that could just as well be exactly what you expect from your target audience!
ELT isn't explained, and probably a few other terms as well. It's just not clear what either the value or purpose is.
In my opinion, that is.
Instead of trying to save space in your destination app by filtering data and only pushing what you need into your Database/Datawarehouse (Snowflake, Redshift, Postgres, MSSQL, etc) throw all of your data from your sources into the Database. They are super fast and storage is cheap. The expensive thing now is DEV time so optimize for that.