Software Applications Programming Errors and solutions.

1. Buffer pool too small 2. Inadequate Disk I/O subsystem 3. I/O bottleneck 4. Missing Indexes 5. Low index usage like  poorly design indexes 6. Temp DB contention 7. Data and Log file are on same drive 8. Slow network 9. Client side performance issue 10. Query plan not updated or poor 11.If Update statistics not updated 12.Memory configuration setting not done properly 13.Lock page memory not configured with sql service user.