More logical drives VS more striped drives

I have thought about it many times.
When using more disks in one volume, random IO rises, but not by the same
factor as number of disks.
If load of these two files is the same, then two volumes are better, but if
it is not, one volume is better.
Are you sure that load is always uniformly distributed between files? Than
use separate volumes.
In real world the load always fluctuates so it is not possible to make a
common conclusion.
"Paul Cahill" <anon@.anon.com> pse v diskusnm prspevku
news:%237m9RqZuHHA.3368@.TK2MSFTNGP02.phx.gbl...
>A user called ZoomZoom made the posting below on Tech Republic. As it did
>not get a reply there I am interested to know what the community's opinion
>is.
> Some of my Raid 10's are made up of 8 drives. Would it have been better to
> have created 2 Raid 10's of 4 drives and then have two data files in the
> file group?
> I would expect an 8 drive Raid 10 to give a higher sequential data rate
> but what about random IO when one has many users?
> Regard
> Paul Cahill
> ...
> Posted by ZoomZoom
>
> I have seen many articles that say to place log files separate from db
> files, and use raid 1+0 for the db... but I haven't found anything to
> answer this question for me though (unless it should be so obvious that
> I'm just not seeing it).
> Is it faster for the database to have the tables split into separate files
> and put each file in smaller raid 1+0 configurations or is it faster to
> use the same number of drives in a single raid 1+0. For example: 8 drives
> could be split into 2 raid 1+0 arrays (4 each) or they could be configured
> in one large raid 1+0 array (8 drives). The end result would be striping
> between 2 sets of 2 drives (in the 4 disk array due to 2 being only
> mirrors) or striping between 4 drives (in the 8 disk array).
> I guess another way of looking at the question is how much performance
> does each additional pair of disks in a raid 1+0 array really add. Can an
> 8 disk array handle twice as many IO's as as a 4 disk array? Or does it
> only add maybe 30% more IO ability? If the later, would it make sense to
> add blocks of 4 disk arrays and split the database tables into multiple
> files instead? Would this theory work like putting the logs on separate
> drives from the database files?
> I realize it's an expensive solution... but with the price of database
> per-processor licenses being what they are... it makes sense to try to
> squeeze as much performance out of your database server as possible.
>
I pretty much agree with that explanation. If you know exactly how your
files will be accessed and they compete with each other at a fairly
intensive level you might get better performance from splitting them. This
is true of separating tempdb from data files as well. But if you don't know
or the load is not too high you are most likely better off having a larger
array with all the data files on it. Now placing the log files on another
array is always a good idea.
Andrew J. Kelly SQL MVP
"Jir Lejsek" <jlejsek@.na_volnym_v_cesku> wrote in message
news:urgxfhauHHA.1184@.TK2MSFTNGP04.phx.gbl...
>I have thought about it many times.
> When using more disks in one volume, random IO rises, but not by the same
> factor as number of disks.
> If load of these two files is the same, then two volumes are better, but
> if it is not, one volume is better.
> Are you sure that load is always uniformly distributed between files? Than
> use separate volumes.
> In real world the load always fluctuates so it is not possible to make a
> common conclusion.
> "Paul Cahill" <anon@.anon.com> pse v diskusnm prspevku
> news:%237m9RqZuHHA.3368@.TK2MSFTNGP02.phx.gbl...
>
|||Right that is why I qualified it with knowing "Exactly" how they are used
which is hard to do.
Andrew J. Kelly SQL MVP
"Roy Harvey" <roy_harvey@.snet.net> wrote in message
news:v798831lqurvqepcvtb9q294c4ha95liq9@.4ax.com...
> On Thu, 28 Jun 2007 17:02:37 -0400, "Andrew J. Kelly"
> <sqlmvpnooospam@.shadhawk.com> wrote:
>
> The problem I have with targetting files at particular drives is that
> it tunes for one particular load only. Tune it for the daytime OLTP
> and it could be sub-optimal during heavy duty batch processing at
> night. One big striped set spreads the load pretty evenly across all
> spindles, regardless of load, and regardless of how the load changes
> over time. It might not be as fast in some special instances, but I
> think on average one big set of drives is going to perform as well or
> better. Targetting files also means one more thing for the DBA to
> keep an eye on and worry about changing later when the load changes or
> space grows differently than expected.
> Logs, of course, are another story as everyone knows.
> Roy Harvey
> Beacon Falls, CT

More Info - HELP - Cannot connect to SQL Server 2005 Express

I've installed the SQL Server 2005 Express and also the MS SQL Server Management Studio 2005 Express
But when i load the latter and try to connect to my database I get the below error message.

TITLE: Connect to Server

Cannot connect to DEVCOMP\SQLEXPRESS.

ADDITIONAL INFORMATION:
An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) (Microsoft SQL Server, Error: -1)
For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&EvtSrc=MSSQLServer&EvtID=-1&LinkId=20476
Further Details:

Further to the above error me, I got the following when I clicked on "Surface Area Configuration for Services and Connections"

TITLE: Surface Area Configuration for Services and Connections - localhost
-
Computer localhost does not exist on the network, or the computer cannot be configured remotely. Verify that the remote computer has the required Windows Management Instrumentation components and then try again.
-
ADDITIONAL INFORMATION:
[C:\WINDOWS\assembly\GAC_MSIL\Microsoft.SqlServer.SmoEnum\9.0.242.0__89845dcd8080cc91\Microsoft.SqlServer.SmoEnum.dll] InternalsVisibleTo declarations cannot have a version, culture, public key token, or processor architecture specified. (Microsoft.SqlServer.Smo)
-

|||Check to see if the SQL Server Express service is started.

Also, you may want to change the network settings to accept TCP/IP and remote connections. Check out this blog entry:

http://blogs.msdn.com/sqlexpress/archive/2005/05/05/415084.aspx

Let me know if this doesn't fix your problem.

Thanks,
Rob|||

The remote connectivity is disabled by default. You can activate it using the SQL Server 2005 Surface Area Configuration SQLSAC.EXE.

If localhost is not known, then either your hosts. file is corrupt or blocked by a firewall (for any tests, deactivate the local firewall temporarily). You can use 127.0.0.1 instead of localhost.

The hosts file is located in your windows directory under

C:\windows\system32\drivers\etc\hosts.

Regards
Axel

|||

I have checked out the blog and performed all the steps. I have restarted the services and still no luck.

I am a newbie to webdev so started with the sample personal website. I followed the instructions to the letter but cant get past Ctrl-F5 to initialize without the error.

Where do I goto from here?

Paul

Monitoring Inserted data and comparing against selected data

I made ahuge load script in SQL Server 2000 as i load data from many
tables(select some of each one collumns) into one single table and i
want to test the loaded data against the selected data to make sure
that the loaded data is the same the selected data
is there a code or tool to make this test or monitoring ?? please
urgent ...tamatem wrote:

Quote:

Originally Posted by

I made ahuge load script in SQL Server 2000 as i load data from many
tables(select some of each one collumns) into one single table and i
want to test the loaded data against the selected data to make sure
that the loaded data is the same the selected data
is there a code or tool to make this test or monitoring ?? please
urgent ...

So you did a select ... into query? I'd be curious to know why exactly
you want to compare the two tables. Do you not trust the server to do
it correctly? It isn't really like a file copy or network transfer
where it's subject to errors.|||I agree.

You can trust SQL to do the job correctly or give an error. Just check
for @.@.ERROR to make sure that no error happened. I dont think you would
actually need to check whether the data got inserted properly.

ZeldorBlat wrote:

Quote:

Originally Posted by

tamatem wrote:

Quote:

Originally Posted by

I made ahuge load script in SQL Server 2000 as i load data from many
tables(select some of each one collumns) into one single table and i
want to test the loaded data against the selected data to make sure
that the loaded data is the same the selected data
is there a code or tool to make this test or monitoring ?? please
urgent ...

>
So you did a select ... into query? I'd be curious to know why exactly
you want to compare the two tables. Do you not trust the server to do
it correctly? It isn't really like a file copy or network transfer
where it's subject to errors.