I've worked a bunch on DBs. Do you know exactly what the issue is?
You might want to consider:
1) That maybe the updates are locking rows?
2) Is it maybe in a long running transaction that then blocks all rows within that transaction?
3) If possible running the updates against a different DB? That is storing the user ratings in a different DB.
You might want to consider:
1) That maybe the updates are locking rows?
2) Is it maybe in a long running transaction that then blocks all rows within that transaction?
3) If possible running the updates against a different DB? That is storing the user ratings in a different DB.