I've not seen many corrupted sqlite databases, but because Synapse is not currently storage-efficient you can end up with some terrifying large (100GB+) sqlite databases which might as well be corrupted.

We only ever supported sqlite for ease of tinkering; it was never intended to be used in production, and in retrospect supporting it at all was a mistake.

In terms of synapse storage efficiency and how to improve it, folks may be interested in https://www.youtube.com/watch?v=D5zAgVYBuGk&t=1851s