It's a short, easy query to write. I'm not convinced it's a big need. So, your proposal is basically this: make a metadata table. On every insert or delete fro

It's a short, easy query to write. I'm not convinced it's a big need. So, your proposal is basically this: make a metadata table. On every insert or delete from the table, update the metadata table accordingly. MVCC will make sure anybody reading from it will get the right answer. Is that about right?