[dba-SQLServer] SQL Server 2005 unresponsive

Francisco Tapia fhtapia at gmail.com
Fri Sep 4 12:28:10 CDT 2009


It's not Sql Server ALLOWING the ODBC call to send it to turtle mode, it's
ODBC, that library is inherently slow, and has problems with larger
datasets.

If you are seeing slowness on your SQL Server you'll need to fine tune a few
things


First check the size of of your transaction logs, whenever they exceed 50%
of the data file size, then you can begin running into some performance
problems.  (normally i see this if my transaction log file is 2x or more
than my data file.)

also check the tempdb

When you are MOVING a lot of data around, the way you are, you want to have
each data partition on it's own set of spindle disks, this applies largely
to your transaction logs, because you don't want to loose the data but you
want the system to process extremely quick, you should look into raid 10 if
you can afford it. For TempDB it's possible to squeeze a lot of performance
on the disks, first tempdb is always rebuilt when the server comes back up,
and all data is just temporary, so you could go with a pair of raid 0
drives, possibly 3 spindles if you need the extra speed.  Striping is the
fastest possible solution to speeding up IO,  ideally of course you'll want
to have this on it's own separate i/o card and own channel if possible.

benchmark your system by running it through the paces of the SQLIO
benchmarking tool from MS
http://www.microsoft.com/DOWNLOADS/details.aspx?familyid=9A8B005B-84E4-4F24-8D65-CB53442D9E19&displaylang=en
and benchmark as you move towards faster drives to see the new throughput.
In your case you might be easily impressed by moving the tempdb to a set of
raid 0 drives.


-Francisco
http://sqlthis.blogspot.com | Tsql and More...


On Fri, Sep 4, 2009 at 10:12 AM, jwcolby <jwcolby at colbyconsulting.com>wrote:

> Jim,
>
> Thanks for the response.  I have to agree, it does seem to be something
> ODBC / Access related in
> that pretty much everything I do directly inside of SQL Server works just
> fine.  It is annoying that
> SQL Server would ALLOW an ODBC call from Access to cause it to go into
> turtle mode though.
>
>  > Have you tried .Net?
>
> Oddly enough I have, but it was some time ago.  I was doing this stuff in
> VB.Net / ADO, but I was so
> slow at the .Net development that when I needed to "get something done" I
> just went back to Access.
>  I cannot make any valid comparisons however as back when I was doing the
> .Net work I also was a
> complete nube at the SQL Server stuff as well, couldn't even write a SP.
>
> I am taking a C# class now and will be moving squarely into C# in the
> future.  I have pretty much
> made a decision to make that my future.  But in the here and now...
>
> John W. Colby
> www.ColbyConsulting.com
>
>
> Jim Lawrence wrote:
> > I think the issue is Access related and not MS SQL. Had exactly the same
> > issues when connected to an Oracle DB. I ended up writing code that would
> > save my results to a temporary table, in the Oracle DB and then would
> have
> > Access just retrieve the table results.
> >
> > The single process step of gathering the data and downloading a
> recordset,
> > via ADO would sometimes cause a hang up. If I used ODBC, it would always
> > cause a hold up especially on larger data sets.
> >
> > Have you tried .Net?
> >
> > Jim
>
>
>



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