Re: How the SQL Server World Lives

I understood it that a save could detect a corrupt file, not that it would be the one corrupting it.

Glenn

-----Original Message-----
From: Charles Wilt <charles.wilt@xxxxxxxxx>
Sender: midrange-l-bounces@xxxxxxxxxxxx
Date: Tue, 29 Jan 2013 17:12:43
To: Midrange Systems Technical Discussion<midrange-l@xxxxxxxxxxxx>
Reply-To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Subject: Re: How the SQL Server World Lives

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/
>
>
>
> --

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