Find queries that generate user seeks on missing index DMV's

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Find queries that generate user seeks on missing index DMV's

SkyBox

SSCarpal Tunnel

Points: 4288
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July 22, 2011 at 3:14 pm

#244556

Just beginning to dig into DMV's. Wondering if I can tie the query below to another DMV that will show the full query text?

I need to test the effectiveness of adding the missing indices, query by query. Recommendations?

SELECT user_seeks * avg_total_user_cost * ( avg_user_impact * 0.01 ) AS [index_advantage]

, migs.user_seeks

, migs.last_user_seek

, mid.[statement] AS [Database.Schema.Table]

, mid.equality_columns

, mid.inequality_columns

, mid.included_columns

, migs.unique_compiles

, migs.avg_total_user_cost

, migs.avg_user_impact

FROM sys.dm_db_missing_index_group_stats AS migs (NOLOCK)

INNER JOIN sys.dm_db_missing_index_groups AS mig (NOLOCK) ON migs.group_handle = mig.index_group_handle

INNER JOIN sys.dm_db_missing_index_details AS mid (NOLOCK) ON mig.index_handle = mid.index_handle

WHERE mid.database_id = DB_ID()

ORDER BY ORDER BY index_advantage DESC
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Gail Shaw SSC Guru Points: 1004494 More actions · Answer 1

No, there's no DMV you can join to to get the query text. The optimiser just drops the missing index info in there, it doesn't tie it to a query.

If you're feeling brave you can interogate the plan cache, looking for the <missing indexes /> elements in the plan's XML.

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

We walk in the dark places no others will enter
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SQLRNNR SSC Guru Points: 281324 More actions · Answer 2

And along the note that Gail mentioned, read this blog post.

http://sqlserverpedia.com/blog/sql-server-2005/can-you-dig-it-%E2%80%93-missing-indexes/">

http://sqlserverpedia.com/blog/sql-server-2005/can-you-dig-it-%E2%80%93-missing-indexes/

Jason...AKA CirqueDeSQLeil
_______________________________________________
I have given a name to my pain...MCM SQL Server, MVP
SQL RNNR
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mister.magoo SSC-Forever Points: 47068 More actions · Answer 3

And Brad Schulz wrote an interesting blog post http://bradsruminations.blogspot.com/2011/04/index-tuning-detective.html

It does delve into the query cache and although I cannot attest to it's usefulness as I haven't tried it yet, it does make for interesting reading and he has some sample queries that you might like.

MM

select geometry::STGeomFromWKB(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