Mat Stephen's SQL Server WebLog : Post Event Follow Up

Follow up on XPs and SQLiMail question from SQL Server™ 2005 Management and Admin TechNet evening 28/7/05

Mat_Stephen — Fri, 12 Aug 2005 16:36:00 GMT

Sorry for the delay in getting these answers posted but my trip to the US and some hols have got in the way.

I was asked if SQL Express could handle Extended Stored Procedures unlike msde. The answer is msde can handle XPs and so can SQL Express. However this functionality may well be deprocated at some stage and one is advised to use CLR assemblies instead as they will be more reliable and easier to create.

The other question was can SQLiMail consolidate sent emails from different servers. The answer is no, you will need to write a job to do this, Sent emails can be accessed from sysmail_sentitems or sysmail_mailitems views.

New Microsoft SQL Server 2005 Upgrade Advisor - CTP June Refresh

Mat_Stephen — Fri, 29 Jul 2005 18:33:00 GMT

Last night at the TechNet evening in Reading I was asked if we are planning an upgrade event. I couldn't say last night, but now I'm glad to say yes we are. In the week starting 5th Decemer we are planning a SQL focus day - during which we will cover this topic.

However in the meantime those of you keen to learn more right now should check out this tool which analyses SQL2000 apps for potential upgrade issues to Yukon.

http://www.microsoft.com/downloads/details.aspx?FamilyID=cf28daf9-182e-4ac2-8e88-f2e936558bf2&DisplayLang=en

Follow up on Database snapshot performance question from SQL Server™ 2005 High Availability TechNet evening 21/6/05

Mat_Stephen — Wed, 22 Jun 2005 22:31:00 GMT

Follow up on Database snapshot performance question from SQL Server™ 2005 High Availability TechNet evening 21/6/05

Question; how does a snapshot database perform compared to the original database when it comes to querying – can it make use of the indexes on the original database?

Thanks to my colleague in the States, Lewis Bruck, I can confirm that all pages in the database (including index pages) are available to the snapshot database.

Query performance on the snapshot compared to the original database depends on a number of factors: the snapshot is read-only, so fewer locks are obtained, but copied data can introduce disk fragmentation requiring more read costs.

Follow up on Replication Columns question in my TechNet SQL 2005 presentation (14/6/05)

Mat_Stephen — Wed, 22 Jun 2005 17:55:00 GMT

Question: How many columns does SQL Server 2005 allow in a published article (SQL Server 2000 was linited to 254)?

Answer: The column limit for transactional replication, I'm informed, is now in excess of 1000.

Follow up on Witnesses question from SQL Server™ 2005 High Availability TechNet evening 21/6/05

Mat_Stephen — Wed, 22 Jun 2005 15:29:00 GMT

Database Mirroring:

How many witness can you have in quorum? - One

How many witnesses can you have on one box? - Many

More follow up from my TechNet SQL 2005 presentation (14/6/05) - SMP boxes and database files

Mat_Stephen — Fri, 17 Jun 2005 00:13:00 GMT

During my TechNet presentation on Tuesday evening (14/6/05 in Reading), I got a little side tracked and, while talking about partitioning in SQL 2005, found myself drawing my audiences’ attention to the fact that only one thread can access a database file at any one time. This fact being the foundation to my post http://blogs.technet.com/mat_stephen/archive/2005/02/02/365325.aspx

I misused the word access, more than one thread can access a database file at any one time for ‘read’. What I had in mind was the fact only one thread can open a file for ‘write’ – hence the blog entry above.

In the same breath I said that ‘not many people know this’, and they don’t. Not surprisingly I’ve since had some emails on this subject, all asking for more information.

For sometime I’ve struggled to find evidence for my assertions in this area – forgetting how I was first alerted to the issue and only being able to point to the win32 openfile api call for evidence.

Well I’ve now found the documentation I’ve been looking for all this sometime. At last I’ve found it again here http://www.microsoft.com/technet/prodtechnol/sql/2000/maintain/rdbmspft.mspx, look under the heading 'Parallel Data Retrieval'.

For those of you still keen to find out more in this area, I point you to another document dealing with a real scenario involving a SAN and the added complexity introduced by a SAN. Checkout this 10Tb project to detail the Human Genome @ http://www.microsoft.com/sql/techinfo/administration/2000/rosetta.asp.

Hope this helps clarify this important and little appreciated fact. I've seen the startling evidence myself - but I know this is not enough for you hard nose sceptics amongst you - I know this because I too am a hard nosed sceptic.

Peer to Peer replication demo code from SQL Server 2005 TechNet evening on the 14th June at our Reading office

Mat_Stephen — Thu, 16 Jun 2005 17:47:00 GMT

You can find all the code @ http://blogs.technet.com/mat_stephen/articles/406459.aspx

London roadshow follow up: Selective execution of SQL Server Integration Service Tasks and Transforms

Mat_Stephen — Tue, 14 Jun 2005 16:42:00 GMT

I had a question, at the London roadshow (8th June), which I wasn’t sure if I could answer reliably, so I promised to blog the answer.

The question: “Can I run selected (with mouse) tasks and transforms from inside the SQL Server Integration Services package designer?”

The answer I have is, for transforms, no you can’t. For tasks you can – or at least just about. You can select single or multiple tasks and then right mouse click and choose to 'disable' the selected task(s) – whereupon they appear greyed out. Then when the package runs, those disabled tasks are not included in the run.