Ever since the old MS-DOS days, the Windows OS family has supported a special ‘null device’ – NUL. Notice the single ‘L’. This is a ‘reserved’ device identifier which you can use as a path. The special thing about this null device (NUL) is that it essentially swallows whatever is sent to it. NUL and…


Data Quality Services (DQS) and Failover Cluster instances

One of my customers made the observation that it is not possible to uncheck the Data Quality Services component in the Feature Selection screen in SQL Server 2012 setup. The interesting thing was that she clearly recalled that earlier it was possible to select it (the default was unchecked), and we wondered what changed that…


SQL 2014 In-Memory OLTP ‘Hekaton’: training videos and white papers

Personally, the feature I am most excited about in SQL Server 2014 is the In-Memory OLTP (codenamed ‘Hekaton’) feature. Since SQL Server CTP1 was released, a lot of my interactions with colleagues and customers have revolved around this new feature and the one question everyone has is, how do I get started? Well, here’s a…


The Top 10 Issues uncovered by the SQL Server Risk Assessment Program (SQLRAP)

Firstly – Happy New Year, everyone! In my job as a Principal Premier Field Engineer at Microsoft Services, I am a regional lead for a proactive risk identification program called the SQLRAP. For over 7 years now we have evolved this from a manually conducted ‘Health Check’ offering to a highly automated and comprehensive Risk…


Extra T-SQL checks to complement SQL Upgrade Advisor

Background More and more customers are looking to upgrade to SQL Server 2012, which offers some exciting features like AlwaysOn Availability Groups, ColumnStore Indexes and much more. As part of my job in the Microsoft Premier Field Engineering team, we are called upon by customers to assess their readiness to upgrade to the new version….


Where can I download SQL 2012 Upgrade Advisor?

This post is a really quick one… Let’s say you are planning to check your SQL Server and T-SQL code for any potential breaking changes in SQL 2012. So you use Upgrade Advisor. Let’s say you want to download it, rather than get it from the installation media (the MSI can be found under \Servers\redist\Upgrade…


AlwaysOn Availability Groups Connectivity Cheat Sheet

Today we were discussing the AlwaysOn connectivity options, and the various combinations therein of Readable Secondary setting and the connection strings became very complex. So I have summarized all the possible outcomes in the pivot tables below. For convenience, we have two tables. The first table covers the cases when the Primary Replica is set…


AlwaysOn Availability Groups Listener: connectivity details

Today in some discussions with my colleagues we were looking at the AlwaysOn Listener which allows SQL Server client applications to be abstracted from the details of the AlwaysOn Availability Group implementation. On the surface, The Listener essentially is a cluster resource pair – a Virtual IP and a Virtual Network Name. But on deeper…


‘No Disks suitable for cluster disks’: one more possible cause

Today in the lab I was working on a test 3-node cluster. I was using Hyper-V for this. We normally use the iSCSI Software Target for testing, so I had set that up on a central VM and then published the target to all the VMs. The disks were seen in the disk management of…


T-SQL Anti-pattern of the day: ‘all-in-one’ queries

Scenario A common requirement for enquiry queries on an OLTP database is to have search criteria which are very specific (‘get me details for for OrderID = NNNN’) and also the occasional reports which ask for all the orders (‘get me all the orders, no questions asked’.) Here is a sample from AdventureWorks which illustrates…