USE THIS: sp_helpindex - Kimberly L. Tripp. Since I’ve rewritten sp_helpindex a few times, I have a few blogs posts in this category.
Each time I do an update I’ll make the NEW version titled USE THIS and I’ll change all others to (OLD). The point of this updated version of sp_helpindex is to add details for newer functionality (included columns and filters) as well as better describe what’s REALLY in your indexes (at the leaf level AND up the b-tree). This particular version won’t error for new index types AND it’s “generic” and not version specific (meaning you don’t have to have an sp_SQLskills_SQL2012_helpindex and instead just have one sp_SQLskills_helpindex across versions). Snapshot Isolation in SQL Server. Snapshot isolation enhances concurrency for OLTP applications.
Once snapshot isolation is enabled, updated row versions for each transaction are maintained in tempdb. A unique transaction sequence number identifies each transaction, and these unique numbers are recorded for each row version. The transaction works with the most recent row versions having a sequence number before the sequence number of the transaction. Newer row versions created after the transaction has begun are ignored by the transaction. The term "snapshot" reflects the fact that all queries in the transaction see the same version, or snapshot, of the database, based on the state of the database at the moment in time when the transaction begins.
Snapshot isolation uses an optimistic concurrency model. Snapshot isolation must be enabled by setting the ALLOW_SNAPSHOT_ISOLATION ON database option before it is used in transactions. Effective Clustered Indexes - Simple Talk. Clustered indexes are the cornerstone of good database design.
A poorly-chosen clustered index doesn’t just lead to high execution times; it has a ‘waterfall effect’ on the entire system, causing wasted disk space, poor IO, heavy fragmentation, and more. This article will present all the attributes that I believe make up an efficient clustered index key, which are: Narrow – as narrow as possible, in terms of the number of bytes it storesUnique – to avoid the need for SQL Server to add a “uniqueifier” to duplicate key valuesStatic – ideally, never updatedEver-increasing – to avoid fragmentation and improve write performance By explaining how SQL Server stores clustered indexes and how they work, I will demonstrate why these attributes are so essential in the design of a good, high-performance clustered index.
In order to understand the design principles that underpin a good clustered index, we need to discuss how SQL Server stores clustered indexes. Let’s look at the B-tree again. Narrow. Sql server - What do Clustered and Non clustered index actually mean? How to Drop Database in SQL Server by Closing Existing Connections - MyTechMantra.com. Microsoft sql server error 18456 login failed for user. In this blog post I will show you reasons why you might be getting SQL Server error 18456 and show you how you may be able to resolve it.
Contents 18456 Error overview When connecting to Microsoft SQL Server and trying to use usually SQL Authentication method you may get event ID error 18456 login failed for user you provided. See below example. This usually means that your connection request was successfully received by the server name you specified but the server is not able to grant you access for a number of reasons and throws error: 18456. Want to easily improve your SQL Server Skills? Before you dive in If you are NOT a DBA (Server Administrator) then read this. We had a number of online private chats using our website chat feature and we have identified there are a number of situations where you cannot do anything about it! Before you start "fixing" it please go through the list below: Our article did not help you but you have found a solution?
Potential causes How to fix? Take care Emil. Ssis - Microsoft TechNet Search. Resources for IT Professionals Sign in United States (English)
Disk Partition Alignment Best Practices for SQL Server. Writers: Jimmy May, Denny Lee Contributors: Mike Ruthruff, Robert Smith, Bruce Worthington, Jeff Goldner, Mark Licata, Deborah Jones, Michael Thomassy, Michael Epprecht, Frank McBath, Joseph Sack, Matt Landers, Jason McKittrick, Linchi Shea, Juergen Thomas, Emily Wilson, John Otto, Brent Dowling Technical Reviewers: Mike Ruthruff, Robert Smith, Bruce Worthington, Emily Wilson, Lindsey Allen, Stuart Ozer, Thomas Kejser, Kun Cheng, Nicholas Dritsas, Paul Mestemaker, Alexei Khalyako, Mike Anderson, Bong Kang Published: May 2009 Applies to: SQL Server 2008 Summary: Disk partition alignment is a powerful tool for improving SQL Server performance.
The following topics are also included: background information, implementation, vendor considerations, two essential correlations, valid starting partition offsets, and the simple protocol to align partitions, define file allocation unit size, and assign drive letters. You can also download a Microsoft Word version of this article. Terms Description. SQLPro : le SQL, tout le SQL, rien que le SQL & les bases de données relationnelles. Open Source Project Hosting.