Lucy, You Got Some 'Splainin to Do!' Quest Software's latest community initiative, Windows Azure-based Project Lucy, has debuted! Project Lucy is part infrastructure analytics, part social media experiment, and part performance data warehouse. The best things about Project Lucy include: It’s Free - just like our SQLServerPedia ...

When you have some data on a SQL Server instance (say SQL01) and you want to move the data to another SQL Server instance (say SQL02) through openquery(), you can either push the data from SQL01, or pull the data from SQL02.   To push the data, you can run a SQL script like the following on SQL01, which is the source server:   -- The ...

In an earlier post, I highlighted that linked server security configuration can have a huge performance impact, and complained that this was not properly documented in SQL Server Books Online and filed a Connectitem for this. Good news is that in Books Online for SQL Server 2008 R2,  Microsoft has revised the documentation, and included the ...

It’s a well known good practice to control the batch size when you perform large data changes. For instance, you may need to purge a large amount of data monthly, and if you delete them all in one shot, you may blow up your transaction log. Therefore, it's wise that you chop up the total amount of data to be deleted into smaller chunks and delete ...

In SQL Server, it is rather handy to retrieve data from a different SQL Server instance and use the result locally in another SQL statement for further processing. In theory and in the set purists’ fantasy land, it shouldn’t matter where you get your data or even how you get the data as long as you can use them to further compose a set-based ...

Is it better to move data to procedures or move procedures to data?   The answer is, of course, “it depends.” Let’s consider a scenario where you have two SQL Server instances: ServerA and ServerB, and you have a procedure on ServerB (call it procB), but need to access data on ServerA.   Three database solutions are ...

I posted the following SQL Server challenge yesterday:   Describe a reproducible workload that would see significant throughput improvement when trace flag 1118 is enabled.   In response, Konstantin Korobkov wanted to know whether the number of data files in tempdb would make a difference.   I did test that scenario and did ...

SQL Server can run in one of two modes: thread mode or fiber mode. By default, SQL Server runs in thread mode in which a SQL Server worker is associated with a Windows thread throughout all phases of its execution. This can be changed with the sp_configure option ‘Lightweight Pooling’. When Lightweight Pooling is turned on, SQL Server runs in ...

While at the PASS Community Summit in November 2008, I had the pleasure of attending a handful of excellent presentations.  One of the best was delivered by Mike Ruthruff (& not just because he shilled for my presentation on disk partition alignment later that day—though I suspect he contributed to my session being SRO). Mike is a ...

In my previous post on the performance impact of having a large number of virtual log files (VLFs) in a transaction log, I showed that a large number of VLFs could be very bad for SQL Server 2008 performance. The test workloads were large batch delete, update, and insert. In other words, they were single monolithic transactions that ...