Clik here to view.
Minimizing the impact of DBCC CHECKDB : DOs and DON'Ts
Your responsibilities as a DBA (or <insert role here>) probably include things like performance tuning, capacity planning, and disaster recovery. What many people tend to forget or defer it...
View ArticleClik here to view.
Optimization Phases and Missed Opportunities
There are two complementary skills that are very useful in query tuning. One is the ability to read and interpret execution plans. The second is knowing a bit about how the query optimizer works to...
View ArticleClik here to view.
Performance Surprises and Assumptions : DATEDIFF
It is very easy to prove that the following two expressions yield the exact same result: the first day of the current month. SELECT DATEADD(MONTH, DATEDIFF(MONTH, 0, GETDATE()), 0), CONVERT(DATE,...
View ArticleClik here to view.
New Trace Flag to Fix Table Variable Performance
It has long been established that table variables with a large number of rows can be problematic, since the optimizer always sees them as having one row. Without a recompile after the table variable...
View ArticleClik here to view.
Properly Persisted Computed Columns
Pretty much every computed column related performance problem I have encountered over the years has had one (or more) of the following root causes: Implementation limitations Lack of cost model support...
View ArticleClik here to view.
Setting and Identifying Row Goals in Execution Plans
Introduction The SQL Server product documentation is a bit light on the topic of row goals. The main official references are in: Hints (Transact-SQL) – Query (FAST and DISABLE_OPTIMIZER_ROWGOAL hints)...
View Article