gistfile1.txt

const deletionWorkpool = workpool(retry by default, retry 10+ times, concurrency = 10)

// Called by the user, public & fast. You can retain the workpool
// job id if you want to be able to indicate
// if the deletion is done yet.
deleteAll -> mutation {
   deletionWorkpool.enqueueAction(internal.deleteAllUserMessages, {user})
}

// Drive many small transactions clearing batches while some exist.
deleteAllUserMessages -> internalAction {
   do {
      const more = ctx.runMutation(internal.deleteUserMessageBatch, ctx.user);
   } while (more)
}

// Simple mutation.
deleteUserMessageBatch -> internalMutation {
   const batch = ctx.db.query("messages").withIndex("by_user", ...).take(51)
   // map over and delete 50
   return batch.length > 50
 }