February 2009 - Posts

• Table Scan - Aggregate Cost Structure

  In the previous post, I mention that in an earlier post on IO cost structure, that the cost of a table scan was approximately 1 CPU-micro sec per page, plus approximately 0.05 us per row for just a SELECT COUNT(*) This was calibrated on a 2-way Xeon 5430 Read More... Posted Friday, February 27, 2009 4:46 PM by jchang | 1 Comments Filed under: cost based optimizer, Hardware, Performance

• SQL Server Fast Track Data Warehouse

  This came out on the Microsoft website. I have not had time to look over the hardware configuration carefully. Of course the recommended storage is a SAN, vendors love to sell very high margin products when there are perfectly good merely high margin Read More... Posted Tuesday, February 24, 2009 4:46 PM by jchang | 31 Comments Filed under: Data Warehouse, Performance, Storage

• Nehalem, Shanghai, and Dunnington performance notes

  Back in March 2008, I discussed the SAP SD 2 Tier results for some AMD Opteron and Intel Xeon systems. Here are some more recent results. All Opteron and Xeon processors below are on the 45nm process except for the Opteron 8360, which is a 65nm product. Read More... Posted Monday, February 23, 2009 2:46 PM by jchang | 9 Comments Filed under: Hardware, Performance

• Run-time Execution Plan Options

  What are the top core SQL Server engine performance issues today, after all the improvements that have gone into 2005 and 2008? (I am excluding matters beyond the power of Microsoft, like eliminating bad developers.) SQL Server already has statement level Read More... Posted Saturday, February 21, 2009 2:11 PM by jchang | 3 Comments Filed under: Optimizer, Performance, Query Hints