MIDRANGE dot COM Mailing List Archive



Home » MIDRANGE-L » January 2013

Re: How the SQL Server World Lives



fixed

Jim,

I'm a bit surprised at that...I'd expect a SAVE operation to be 99.9% read
only. I don't see how a read operation could corrupt an object.

Save-while-active, maybe...

Anybody, looking at you Chuck ;) , know the details?

Charles


On Tue, Jan 29, 2013 at 5:01 PM, Jim Oberholtzer <
midrangel@xxxxxxxxxxxxxxxxx> wrote:

To the contrary; Save operations that are killed in the middle, or fail
for a multitude of reasons will cause a damaged object. I've probably
called in 15 - 20 PMRs over the years and had one critsit over that
very topic. The critsit was while I was VP IT and we were down for
several days. It happened while I as at COMMON in Nashville, I remember
it vividly. Ask Larry what my mood was like that week! The only thing
that made that week worse was Al Barsa passing.

You are correct that a damaged object will not be saved properly, but a
save operation that fails/or is killed (end immediate) can cause a
damaged object as well.

Jim Oberholtzer
Chief Technical Architect
Agile Technology Architects


On 1/29/2013 3:49 PM, Charles Wilt wrote:
Jim,

I think you've got it backward...

I don't believe it even possible for a SAVE to damage an object. But a
damaged object is often detected during the SAVE operation.

Charles


On Tue, Jan 29, 2013 at 4:45 PM, Jim Oberholtzer<
midrangel@xxxxxxxxxxxxxxxxx> wrote:

The question of if a damaged object is considered a corrupted file
then
yes, I have seen it. Usually it's as the result of a Save/Restore
operation that failed, but it does happen.

Jim Oberholtzer
Chief Technical Architect
Agile Technology Architects


On 1/29/2013 3:02 PM, Roger Harman wrote:
> A recent article, "My SQL Server Database is Corrupt - Now
What?!", had
some
> interesting statements from the author:
>
>
>
> . I was asked how often corruption really occurs in the
real
world.
> My answer was, "hundreds to thousands of times every week across
the
world,
> in the tens of millions of SQL Server databases.".
>
> . Every single week I receive multiple emails asking for
some
advice
> about corruption recovery. When I'm teaching about corruption in
our High
> Availability and Disaster Recovery Immersion Event, I always
tell the
class
> that I expect every DBA to see database corruption at some point
during
> their career.
>
> . I'll end by saying this: if you think that corruption
won't
happen
> to you at some point in your career, I think you'll be
surprised. Be
> prepared!
>
>
>
> I'm curious.. How many of you have seen corruption on our
platform? In
25+
> years on S/38, AS/400, and IBM-i, I have NEVER had an issue with
corrupt
> files/tables. In 1 year of SQL Server at my former employer, I
saw it
> happen at least 3 times. I was shocked but the Microsoft bigots
in the
> company just shook it off as status quo.
>
>
>
> Here's the article but you have to be a member to read it.
> http://www.sqlservercentral.com/articles/Corruption/96117/
>
>
>
> --
--
This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list
To post a message email: MIDRANGE-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/midrange-l
or email: MIDRANGE-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/midrange-l.







Return to Archive home page | Return to MIDRANGE.COM home page

This mailing list archive is Copyright 1997-2014 by MIDRANGE dot COM and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available here. If you have questions about this, please contact