SQL Server 2008 DMV's Relationship mapping

Microsoft has introduced the concept of DMV’s (Dynamic Management Views) in SQL Server 2005 and concept is extended to SQL Server 2008 also with additional DMV's for mirroring , memory management etc.

Microsoft has recently released the latest “System Views Map” for SQL Server 2008 which shows the key system views and the relationships between them. You can download the latest System Views Map at

http://www.microsoft.com/downloads/details.aspx?FamilyID=531c53e7-8a2a-4375-8f2f-5d799aa67b5c&displaylang=en

The updated “System views Map” for SQ Server 2005 also can be downloaded at

http://www.microsoft.com/downloads/details.aspx?familyid=2EC9E842-40BE-4321-9B56-92FD3860FB32&displaylang=en

Index maintenance using DMV’s in SQL Server 2005

SQL Server 2005 provides more flexible ways handling index maintenance activities using DMV (Dynamic Management View’s). The DMV’s can be effectively used to identify the index status such as

• Indexes that requires maintenance activities such as reindexing / reorganizing
• List of indexes that are going for index scan
• List of not used indexes

Tables with indexes that require maintenance

SELECT OBJECT_NAME(OBJECT_ID) TableName,
( SELECT NAME FROM SYS.INDEXES
WHERE OBJECT_ID = A.OBJECT_ID
AND INDEX_ID = A.INDEX_ID) IndexName
FROM SYS.DM_DB_INDEX_USAGE_STATS A
WHERE USER_SEEKS >0 AND USER_SCANS >0
AND OBJECT_ID > 97
AND DATABASE_ID = 5
ORDER BY USER_UPDATES, USER_SEEKS DESC

Tables with Indexes going for Scan

SELECT OBJECT_NAME(OBJECT_ID) TableName ,
( SELECT NAME FROM SYS.INDEXES
WHERE OBJECT_ID = A.OBJECT_ID
AND INDEX_ID = A.INDEX_ID) IndexName
FROM SYS.DM_DB_INDEX_USAGE_STATS A
WHERE INDEX_ID <> 0
AND OBJECT_ID > 97
AND DATABASE_ID = 5
AND USER_SCANS > 0 ORDER BY USER_SCANS DESC

Tables with not used indexes

SELECT OBJECT_NAME(OBJECT_ID) TableName,
(SELECT NAME FROM SYS.INDEXES
WHERE OBJECT_ID = A.OBJECT_ID
AND INDEX_ID = A.INDEX_ID) IndexName
FROM SYS.DM_DB_INDEX_USAGE_STATS A
WHERE USER_SEEKS = 0
AND USER_SCANS =0
AND USER_LOOKUPS =0
AND USER_UPDATES = 0
AND OBJECT_ID > 97
AND INDEX_ID <> 0
AND DATABASE_ID = 5