In osm2pgsql there is that code that stores the raw data it gets from the input files and makes it available to other parts of osm2pgsql for further processing. This code is called, in osm2pgsql-speak, the “middle”. There are two implementations of this “middle”, one stores the data in RAM and doesn’t support updates. The other stores the data in the database and supports updates. Back in 2020 I started looking into that code to see what could be improved. In 2021 we released version 1.5.0 which contained a basically rewritten RAM middle. And now, in 2023, I finally got around to improving the database middle.

Taginfo has as its goal to find and collect all useful knowledge about OSM tags and make it accessible. But taginfo can’t do everything. That’s why it has always linked to tools that “do something with OSM tags”, the most popular one is probably Overpass Turbo.