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Re: Do log files demand serialization?

From: Kendall <kendallwillets_at_yahooooo.com>
Date: Thu, 14 Feb 2002 20:47:31 -0800
Message-ID: <u6p4n3ftfblo20@news.supernews.com>


If it's any help, logs don't have to record the updates for a transaction contiguously. Each action in the AIJ log is keyed by transaction ID, and then (I believe) a "commit" action is recorded synchronously when the client commits.

Are you assuming that the log has to be locked to get the updates in serial order? I believe that transaction ID's are used to sort the updates during recovery, rather than requiring that they go into the log serially.

Some of the details of how to allocate transaction ID's are fuzzy to me, however. It seems like the logs are OK with serializable transactions, but only if the transaction ID's are allocated serially, eg from a single counter, so that it's clear what the serializable order is. Is that the case in most RDBMS's?

In article <52e031b9.0202141258.4c468a5e_at_posting.google.com>, "tj bandrowsky" <tbandrow_at_unitedsoftworks.com> wrote:

> The only question I would have then, would be, is how long are the RUJ
> and AIJ exclusively locked? Wouldn't transaction logs have to be
> locked?
Received on Thu Feb 14 2002 - 22:47:31 CST

Original text of this message

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