Archives of the TeradataForum
Message Posted: Sat, 26 Apr 2003 @ 06:04:28 GMT
| Subj: || || Re: Deadlock Question |
| From: || || Walter, Todd A |
- Only one transaction is aborted, the other(s) will complete.
- There are two levels of deadlock detection. If the deadlock is detectable in a single AMP, then the deadlock will be detected instantly
when the lock request causing the deadlock is received and the request asking for that lock will be the victim. If the deadlock is not
visible in a single amp but is distributed across multiple amps, then the global deadlock detection mechanism will identify the deadlock and
pick the victim. GDLD runs on a periodic basis (DBSControl settable). When it runs it collects blocking information from all the amps,
builds a global waitfor graph and identifies deadlocks. Once a deadlock has been identified, every effort is made to kill the one that has
run for the shortest amount of time so that the lost work and rollback time is minimized.
- Your read views with access locks should not cause any deadlocks.