Re: [Bodington-developers] Locking Issues (Java, Explicit DB, Optimistic DB)

[Peter C. <Pet...@me...>]

> From: Matthew Buckett
> If we updated to TRANSACTION_REPEATABLE_READ=20
> then we don't have to=20
> worry about a read row being modified under our feet.

Sorry, doesn't work - you have to go to SERIALIZABLE on MSSQL at least.
Otherwise:

- A reads (acquires read lock);
- B reads (acquires read lock);
- A adds;
- B adds;
- A updates (tries to upgrade to write lock, waits on B's read lock);
- B updates (tries up upgrade to write lock, system detects deadlock and
rolls back one transaction).

... Causes problems at best, deadlock at worst, I think.

		- Peter