How to tackle SQL Performance issues

Performance degradation can happen due to multiple reasons. The main bottlenecks that would affect performance are:

1. Memory
2. Disk IO
3. CPU
4. Blocking
5. System resource contention
6. Application design problems
7. Queries or stored procedures that have long execution times

Please check the Article below which has articles from Symwise, Connect, Few Querys, 3rd Party Tools and Articles

Articles from SymWise

Creating a maintenance plan in SQL Server 2005 or 2008 to optimize database performance
http://www.symantec.com/docs/HOWTO8589

SQL Tuning and Performance
http://www.symantec.com/docs/HOWTO5289

Notification Server performance issues due to SQL index fragmentation
http://www.symantec.com/business/support/index?page=content&id=TECH28827

Articles from Connect

The Story of a Very Expensive Filter
http://www.symantec.com/connect/blogs/story-very-expensive-filter

Use of SQL Queries and performance
http://www.symantec.com/connect/forums/use-sql-queries-and-performance

SQL Querys

Query to check the largest Column within CMDB

select c.collectionguid, count(*), vi.Name
from collectionmembership c join vItem vi on c.CollectionGuid = vi.Guid
group by collectionguid, vi.Name
having count(*) > 1
order by count(*) desc

This query will help you while troubleshooting on the performance issue to find out the largest table within CMDB

SELECT OBJECT_NAME(OBJECT_ID)
TableName, st.row_count FROM sys.dm_db_partition_stats st
WHERE index_id < 2 ORDER BY st.row_count DESC

Following script find out which are the queries running currently on your server.
SELECT sqltext.TEXT,
req.session_id,
req.status,
req.command,
req.cpu_time,
req.total_elapsed_time
FROM sys.dm_exec_requests req
CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS sqltext

While running above query if you find any query which is running for long time it can be killed using following command.
KILL [session_id]
 

3rd Party Tools and Articles
 

Tools to help database administrators manage the performance of Microsoft SQL Server.

RML Utilities for SQL Server (x86)
http://www.microsoft.com/en-us/download/details.aspx?id=8161

SQL Nexus Tool
SQL Nexus is a tool that helps you identify the root cause of SQL Server performance issues. It loads and analyzes performance data collected by SQLDiag and PSSDiag. It can dramatically reduce the amount of time you spend manually analyzing data.
http://sqlnexus.codeplex.com/

How to troubleshoot SQL Server performance issues
http://support.microsoft.com/kb/298475

HOW TO: Troubleshoot Application Performance with SQL Server
http://support.microsoft.com/kb/224587/en-us