April 2011 - Posts

• Linked servers: set them up in QA

  How do you set up linked servers in your QA environment? You set them up the same as you do in the production environment, right? Why even ask? Correct. There is no difference in the actual steps of setting up a linked server between your QA and prod. Read More... Posted Tuesday, April 05, 2011 3:34 PM by Linchi Shea | 10 Comments Filed under: Best Practices, Linked server, QA

• Performance impact: The cost of doing small lookups in a large batch update

  Lookup tables are widely used in database applications for good reasons. Usually, a lookup table has a small number of rows and looking it up with a join is fast, especially when the table is already cached. Recently, I needed to update every row in many Read More... Posted Monday, April 04, 2011 3:34 PM by Linchi Shea | 3 Comments Filed under: Testing, Best Practices, Performance tuning, Lookup tables Attachment(s): LookupCost.GIF

• There are no sequential or random disk I/Os

  Okay, it’s a bit of a hyperbole. But let me elaborate. I regularly bump into SQL Server discussions, online or elsewhere, in which I hear people speaking with confidence that an operation is so and so because it is doing sequential disk I/Os or because Read More... Posted Friday, April 01, 2011 1:42 PM by Linchi Shea | 4 Comments Filed under: Architecture, Storage, Disk I/O