Q&A: SQL Server

Checklist for Analyzing Slow-Running Queries?
# Use SQL Server Profiler to help identify the slow query or queries. For more information. Use the sys.dm_exec_query_stats and sys.dm_exec_requests dynamic management views to find similar queries that collectively consume a large number of resources.
# How do I analyze the performance of a slow-running query? After you have identified the slow-running query or queries, you can further analyze query performance by producing a Showplan, which can be a text, XML, or graphical representation of the query execution plan that the query optimizer generates. (You can produce a Showplan using Transact-SQL SET options, SQL Server Management Studio, or SQL Server Profiler.)
# Are suitable indexes available? Would adding one or more indexes improve query performance?
# Are there any data or index hot spots? Consider using disk striping. Disk striping can be implemented by using RAID (redundant array of independent disks) level 0, where data is distributed across multiple disk drives.
# Is the query optimizer provided with the best opportunity to optimize a complex query?
# If you have a large volume of data, do you need to partition it? Data manageability is the main benefit of partitioning, but if your tables and indexes on them are partitioned similarly, partitioning can also improve query performance. For more information, see Understanding Partitioning and Tuning the Physical Database Design.