SQL Server Unused Index

Hi,

SQL Server DBA should monitor all indexes and which of indexes are using and which are not.

If the index is not using or using very rare then SQL Server DBA should drop it to not provide extra load to the database.

You can find all indexes usage statistic with following script. Script will generate drop index script also, you can use this script to drop index safely.

SELECT 
o.name
, indexname=i.name
, i.index_id   
, reads=user_seeks + user_scans + user_lookups   
, writes =  user_updates   
, rows = (SELECT SUM(p.rows) FROM sys.partitions p WHERE p.index_id = s.index_id AND s.object_id = p.object_id)
, CASE
	WHEN s.user_updates < 1 THEN 100
	ELSE 1.00 * (s.user_seeks + s.user_scans + s.user_lookups) / s.user_updates
  END AS reads_per_write
, 'DROP INDEX ' + QUOTENAME(i.name) 
+ ' ON ' + QUOTENAME(c.name) + '.' + QUOTENAME(OBJECT_NAME(s.object_id)) as 'drop statement'
FROM sys.dm_db_index_usage_stats s  
INNER JOIN sys.indexes i ON i.index_id = s.index_id AND s.object_id = i.object_id   
INNER JOIN sys.objects o on s.object_id = o.object_id
INNER JOIN sys.schemas c on o.schema_id = c.schema_id
WHERE OBJECTPROPERTY(s.object_id,'IsUserTable') = 1
AND s.database_id = DB_ID()   
AND i.type_desc = 'nonclustered'
AND i.is_primary_key = 0
AND i.is_unique_constraint = 0
AND (SELECT SUM(p.rows) FROM sys.partitions p WHERE p.index_id = s.index_id AND s.object_id = p.object_id) > 10000
ORDER BY reads;

Do you want to learn Microsoft SQL Server DBA Tutorials for Beginners, then read the following articles.

https://ittutorial.org/sql-server-tutorials-microsoft-database-for-beginners/