Re: Bring Online down in middle of transaction rol

Hi! I understand your explanation. To take this further, if I shutdown the system 4 hours into a transaction, will the recovery phase take 4hours (or more)? At 03:34 AM 11/4/97 EDT, you wrote: } } }>What is the effect of bringing Online down in the middle of a }>transaction being rolled back? Is it meant to recover gracefully from }>this kind of thing? If so, in reality, does it actually do so (recover }>gracefully, that is)? }> }>I've got a client who pulled a bone-headed move of running two huge }>deletes at the same time. After eight hours, the 800,000 row locks have }>been exhausted, and all users are locked out of the database. So, we're }>going to have to wait another eight hours, at least, for the }>transactions to roll back. }> }>I'm wondering if there are any ways to speed this process. One thought }>that came to mind was to bring Online down, add more locks, then bring }>it back up. My concern is whether Online is meant to recover gracefully }>from being shut down in a middle of a transaction rolling back. 800,000 }>rows is a lot to modify, so I'm a bit queasy about interrupting that }>kind of transaction. Anybody w/ experience like this? }> }>Is there some other way that I could speed this process to get users }>access to the DB more quickly? } }When online is brought up the recovery process is a two phase recovery. The } first phase (physical recovery) uses the physical log file and is used to } bring the database back to the state that it was at the last checkpoint. Then } begins logical recovery which uses the logical log files. This involves } rolling forward all activity contained in the logical log files. Finally when } the end of the logical log file is encountered, all open transactions are } automatically rolled back. } }Since the recovery begins at the last checkpoint, then re-rolling back a } transaction that was in rollback when the engine was brought down poses no } problem. Basically, whatever was still in an open state will be rolled back. } If it was partially rolled back, it doesn't matter. The recovery process will } complete the roll back. } }Madison Pruet } Best regards, Nigel +-------------------------------------------------------------+ |Name : Edmund Nigel Gall Tel: (868) 636 3153 | |Title : Information Systems Specialist Fax: (868) 679 3770 | |Company: Process Plant Services Limited | |Address: Atlantic Avenue, Point Lisas Industrial Estate | | Point Lisas, Couva, Trinidad & Tobago, W.I. | +----- mailto:nigelg@ppsl.com ------ http://www.ppsl.com -----+