Product:

Microsoft SQL server 2016

Problem:

How is my Index used?

Solution:

List the index in the database:

SELECT OBJECT_NAME(IX.OBJECT_ID) Table_Name
   ,IX.name AS Index_Name
   ,IX.type_desc Index_Type
   ,SUM(PS.[used_page_count]) * 8 IndexSizeKB
   ,IXUS.user_seeks AS NumOfSeeks
   ,IXUS.user_scans AS NumOfScans
   ,IXUS.user_lookups AS NumOfLookups
   ,IXUS.user_updates AS NumOfUpdates
   ,IXUS.last_user_seek AS LastSeek
   ,IXUS.last_user_scan AS LastScan
   ,IXUS.last_user_lookup AS LastLookup
   ,IXUS.last_user_update AS LastUpdate

 

Show if index are fragmented:

SELECT  OBJECT_NAME(IDX.OBJECT_ID) AS Table_Name,
IDX.name AS Index_Name,
IDXPS.index_type_desc AS Index_Type,
IDXPS.avg_fragmentation_in_percent  Fragmentation_Percentage
FROM sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL, NULL) IDXPS
INNER JOIN sys.indexes IDX  ON IDX.object_id = IDXPS.object_id
AND IDX.index_id = IDXPS.index_id
ORDER BY Fragmentation_Percentage DESC

 

List index usage:

SELECT *
FROM
sys.dm_db_index_usage_stats
INNER JOIN sys.objects ON dm_db_index_usage_stats.OBJECT_ID = objects.OBJECT_ID
INNER JOIN sys.indexes ON indexes.index_id = dm_db_index_usage_stats.index_id AND dm_db_index_usage_stats.OBJECT_ID = indexes.OBJECT_ID
WHERE
indexes.is_primary_key = 0 --This line excludes primary key constarint
AND
indexes. is_unique = 0 --This line excludes unique key constarint
AND 
dm_db_index_usage_stats.user_updates <> 0 -- This line excludes indexes SQL Server hasn’t done any work with
AND
dm_db_index_usage_stats. user_lookups = 0
AND
dm_db_index_usage_stats.user_seeks = 0
AND
dm_db_index_usage_stats.user_scans = 0
ORDER BY
dm_db_index_usage_stats.user_updates DESC

 

 

More Information:

Gathering SQL Server indexes statistics and usage information

https://codefibershq.com/blog/useful-sqlserver-queries-commands-and-snippets