I still didn't love the idea of storing the redundant file size, and I considered alternatively creating a virtual SQLite table.
But we'd still have to populate the virtual table still at app load time, which would take ~10s per GB of data
https://www.sqlite.org/vtab.html
Hope you enjoyed following along! Here's the full PR with the fix: https://github.com/mtlynch/picoshare/pull/221
Creating the index is a one-line fix, and it doesn't have the drawback my original PR did of storing a redundant copy of the file size. https://github.com/mtlynch/picoshare/pull/230/files
The last tricky part was writing a SQL migration to populate the sizes of files that were uploaded and stored in the DB before this change. I've never written an update that derives from other data in the DB before, but it wasn't too hard.