html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,issue,performed_via_github_app https://github.com/simonw/datasette/issues/1384#issuecomment-869074182,https://api.github.com/repos/simonw/datasette/issues/1384,869074182,MDEyOklzc3VlQ29tbWVudDg2OTA3NDE4Mg==,2670795,2021-06-26T23:37:42Z,2021-06-26T23:37:42Z,CONTRIBUTOR,"> > Hmmm... that's tricky, since one of the most obvious ways to use this hook is to load metadata from database tables using SQL queries. > > @brandonrobertz do you have a working example of using this hook to populate metadata from database tables I can try? > > Answering my own question: here's how Brandon implements it in his `datasette-live-config` plugin: https://github.com/next-LI/datasette-live-config/blob/72e335e887f1c69c54c6c2441e07148955b0fc9f/datasette_live_config/__init__.py#L50-L160 > > That's using a completely separate SQLite connection (actually wrapped in `sqlite-utils`) and making blocking synchronous calls to it. > > This is a pragmatic solution, which works - and likely performs just fine, because SQL queries like this against a small database are so fast that not running them asynchronously isn't actually a problem. > > But... it's weird. Everywhere else in Datasette land uses `await db.execute(...)` - but here's an example where users are encouraged to use blocking calls instead. _Ideally_ this hook would be asynchronous, but when I started down that path I quickly realized how large of a change this would be, since metadata gets used synchronously across the entire Datasette codebase. (And calling async code from sync is non-trivial.) In my live-configuration implementation I use synchronous reads using a persistent sqlite connection. This works pretty well in practice, but I agree it's limiting. My thinking around this was to go with the path of least change as `Datasette.metadata()` is a critical core function.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",930807135,