Unidentified issues / app hangs after upgrading Dexie to v4 about dexie.js

[dfahlander]

Thanks for the report.

My speculation: One change in dexie@4 is the introduction of a cache used by live-queries only, that allows to reply to liveQueries directly from memory. In case a component has some effect hooks that for some reason trigger an infinite re-render, this could potentially do that much faster (without async waits for indexeddb) with the cache than without it and this could potentially get into a situation where it's consuming all CPU - while without the cache (in dexie 3), it would have left some breath for other tasks while querying indexeddb and not manifest itself the same way.

The cache in dexie@4 can be disabled by providing the option {cache: 'disabled'} to Dexie constructor:

const db = new Dexie("dbname", { cache: 'disabled});

If anyone else would experience this issue, please try whether { cache: 'disabled' } would solve it.

I think that we probably should build a trap into Dexie that stops these possible loops from happening so that a dev could fix the looping code if it happens - we could for example detect if extremely many re-queries happens during a second and then throw an error.