Re: How the SQL Server World Lives -- MIDRANGE-L

How about a Sys/3 15D?. And there, I *HAVE* seen database/file corruption.

Back in the 1976/77 era on a Sys/3 Model 15D, one release caused $FCOMP
under certain circumstances caused the system to overlay the beginning of a
file with the end of the file...or was it the end got overlaid with
the beginning...don't remember, and I don't remember what those
circumstances where....just that we hit them.

To say that it made a mess would be an understatement. Seems it to a very
large file to trigger and our largest file was a Policy History File....so
that damage went on for months before we even knew there was a problem. No
such thing as damaged or corrupt anything back in those days.

$FCOMP's job was to remove blank gaps in the VTOC (Volume table of
contents) and make everything contiguous on the disk.

And then there was Sullivan Payne in Seattle. (aka: Sedgewick James) back
in the late 80's. We had 3 Sys/38's in the computer room with a whole
bunch of external disk drives feeding the 2 production and 1 development
system. Those disk drives where getting old and had exceeded their MTBF
(Mean time between Failure) and so they failed. And this is in the days
WAY before Raid & Mirroring. Not so much database corruption as total and
complete system corruption. The systems side of the house (Myself and 1
other guy) got very good a reloading from backup and could do it in our
sleep....and did do it in our sleep a few times <g>.

Bob Crothers
www.BJsBariatrics.Com
------------------------------------------
If you think dogs can't count, try putting three dog biscuits in your
pocket and then giving Fido only two of them.
~-Phil Pastoret

On Tue, Jan 29, 2013 at 4:02 PM, Roger Harman <roger_harman@xxxxxxxxxxx>wrote:

One of the newsletters I subscribe to is http://www.sqlservercentral.com

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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