SQL doctor Development Blog

Earlier this week I was researching a performance issue on a SQL Server instance using the ‘sys.dm_os_waiting_tasks’ and ‘sys.dm_exec_requests’ DMV’s and noticed a ton of page latch and page io latch waits.  This is nothing unusual when dealing with performance issues and is normally just one of the signs of poorly written queries, missing indexes, [...]

In my previous blog post ‘Parallelism: Hurry up and wait’ I discussed how parallel queries cause CXPACKET waits.  I also covered the common causes for these waits to be high on an OLTP server.  Today I want to finish up my thoughts on the subject and hopefully round out the discussion for both OLTP and [...]

  At the 2010 SQL PASS Summit we had the great pleasure of speaking with the well known SQL Server MVP Pinal Dave (blog).  One of the topics that were discussed was the use of wait stats by SQL doctor for generating recommendations and he agreed to spend extra time with us to discuss his [...]

SQL doctor can be used to identify the cause of deadlocks.  A deadlock is when a cyclic dependency occurs between two or more threads, processes, resources, etc.  This causes one of the processes to be declared the deadlock victim and killed so that the other process can continue.  To identify deadlocks and provide useful information [...]

Improve SQL Server performance by avoiding an implicit conversion in a search predicate.

The ‘Missing Join Predicate’ recommendation (SDR-Q19) given by SQL doctor for a query that results in the cartesian product of two or more tables will help identify bottlenecks in TSQL to improve query performance.