Following are the major problem areas that can degrade SQL Server performance:
- Poor indexing/Bad indexing
- Inaccurate statistics
- Poor query design
- Poor execution plans
- Non-set-based operations, usually T-SQL cursors
- Poor database design
- Excessive blocking and deadlocks
- Excessive fragmentation
- Nonreusable execution plans
- Frequent recompilation of queries
- Improper use of cursors
- Improper configuration of the database log
