Hej,
SQL Server DBA bør overvåge alle indekser og hvilke af indekser der bruger og hvilke der ikke gør.
Hvis indekset ikke bruger eller bruger meget sjældent, bør SQL Server DBA droppe det for ikke at give ekstra belastning til databasen.
Du kan finde alle indeksers brugsstatistik med følgende script. Script vil også generere drop index script, du kan bruge dette script til at droppe indeks sikkert.
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;