issue_comments: 1066006292

If I'm understanding your plugin code correctly, you query the db using the sync handle every time get_metdata is called, right? Won't this become a pretty big bottleneck if a hook into render_cell is trying to read metadata / plugin config?

Reading from sqlite DBs is pretty quick and I didn't notice significant performance issues when I was benchmarking. I tested on very large Datasette deployments (hundreds of DBs, millions of rows). See "Many small queries are efficient in sqlite" for more information on the rationale here. Also note that in the datasette-live-config reference plugin, the DB connection is cached, so that eliminated most of the performance worries we had.

If you need to ensure fresh metadata is being read inside of a render_cell hook specifically, you don't need to do anything further! get_metadata gets called before render_cell every request, so it already has access to the synced meta. There shouldn't be a need to call get_metadata(...) or metadata(...) inside render_cell, you can just use datasette._metadata_local if you're really worried about performance.

The plugin is close, but looks like it only grabs remote metadata, is that right? Instead what I'm wanting is to grab metadata embedded in the attached databases.

Yes correct, the datadette-remote-metadata plugin doesn't do that. But the datasette-live-config plugin does. It supports a __metadata table that, when it exists on an attached DB, gets pulled into the Datasette internal _metadata and is also accessible via get_metadata. Updating is instantaneous so there's no gotchas for users or security issues for users relying on the metadata-based permissions. Simon talked about eventually making something like this a standard feature of Datasette, but I'm not sure what the status is on that!

Good luck!