Sinlge user mode in SQL Server

I was trying to change the isolation level of my database using the ALTER DATABASE statement and the query was running for hours to execute it, because there were ongoing transactions in the db which is preventing the isolation change. I have solved this problem by taking the DB into single user mode before running the alter statement using below script

if(charindex('Microsoft SQL Server 2005',@@version) > 0)
begin
declare @sql varchar(8000)
select @sql = '
ALTER DATABASE ' + DB_NAME() + ' SET SINGLE_USER WITH ROLLBACK IMMEDIATE ;
ALTER DATABASE ' + DB_NAME() + ' SET READ_COMMITTED_SNAPSHOT ON;
ALTER DATABASE ' + DB_NAME() + ' SET MULTI_USER;'
Exec(@sql)
end

Any changes to Database level properties in SQL Server can be done easily through the use of single user mode, which permits only one connection to be made to the database at any time.

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