May 13, 2013 at 4:38 pm
Is there some good queries for checking missing indexes on all tables of a database?
THanks
May 14, 2013 at 2:37 am
try below query
SELECT
mid.statement
,migs.avg_total_user_cost * (migs.avg_user_impact / 100.0) * (migs.user_seeks + migs.user_scans) AS improvement_measure,OBJECT_NAME(mid.Object_id),
'CREATE INDEX [missing_index_' + CONVERT (VARCHAR, mig.index_group_handle) + '_' + CONVERT (VARCHAR, mid.index_handle)
+ '_' + LEFT (PARSENAME(mid.statement, 1), 32) + ']'
+ ' ON ' + mid.statement
+ ' (' + ISNULL (mid.equality_columns,'')
+ CASE WHEN mid.equality_columns IS NOT NULL AND mid.inequality_columns IS NOT NULL THEN ',' ELSE '' END
+ ISNULL (mid.inequality_columns, '')
+ ')'
+ ISNULL (' INCLUDE (' + mid.included_columns + ')', '') AS create_index_statement,
migs.*, mid.database_id, mid.[object_id]
FROM sys.dm_db_missing_index_groups mig
INNER JOIN sys.dm_db_missing_index_group_stats migs ON migs.group_handle = mig.index_group_handle
INNER JOIN sys.dm_db_missing_index_details mid ON mig.index_handle = mid.index_handle
WHERE migs.avg_total_user_cost * (migs.avg_user_impact / 100.0) * (migs.user_seeks + migs.user_scans) > 10
ORDER BY migs.avg_total_user_cost * migs.avg_user_impact * (migs.user_seeks + migs.user_scans) DESC
May 14, 2013 at 3:01 am
Do not automatically create all the indexes that the missing index DMVs suggest, that's a good way to severely over-index and hinder performance.
Evaluate what the missing index DMVs suggest, examine the existing indexes, test the suggestions, implement what's useful.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
May 14, 2013 at 4:09 am
And remember, the missing index information, as is, doesn't relate directly to any query at all. So simply taking that stuff as written, you might be creating an index for a query that was run once and then never again.
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
- Theodore Roosevelt
Author of:
SQL Server Execution Plans
SQL Server Query Performance Tuning
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