Lately I have had the opportunity to work with performance tuning of queries running on the Azure Parallel Data Warehouse (Azure PDW). This has been interesting in that everything you thought you knew about SQL Server DMV’s, writing queries and overall performance tuning is just a little bit different. My goal was to write a query to show me what …
Is a clustered table in SQL Server a BTree or Linked List? When you first learn about the structure behind clustered indexes in SQL Server, you find out that the clustered index is structured as a type of B+Tree where queries that make use of the tree structure to find the rows that you are looking for. However it is not the common …
Earlier in the week I added a blog entry on using the OUTPUT Clause on INSERT Statements, today I will expand it by exploring the use of the OUTPUT clause with UPDATE statements. Generally when you do an UPDATE statement you only get a row count returned, you don’t generally get a result set showing what was changed. With the OUTPUT clause …
Being day 24 of the DBCC Command month at SteveStedman.com, today’s featured DBCC Command is DBCC SHRINKDATABASE. When I first heard about DBCC Shrink Database (many years ago), I immediately thought “what a great feature, run this every night when the system load is low, and the database will be smaller, perform better, and all around be in better shape”. …
Is it a good idea to run DBCC SHRINKDATABASE regularly? Download the sample file ShrinkSample. This article and samples apply to SQL Server 2005, 2008, and 2008R2. This really depends on a number of factors, but generally the answer is NO, it is not a good idea to run DBCC SHRINKDATABASE regularly. For the purpose of this article, I am …