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SQL Server Query for Index Recommendation

Antonios Chatzipavlis
Monday 07 September 2009

Το παρακάτω query είναι πάρα πολύ καλό!!!.

Το ξαναβρήκα τυχαία μπροστά μου καθώς σκάλιζα τα διάφορα scripts που έχω στην βιβλιοθήκη μου. Αν θυμάμαι καλά, γιατί έχει περάσει καιρός, το έχει φτιάξει ένα παλικάρι από την μαμά εταιρία, νομίζω ότι είναι ο Swapnil Bajaj.

Κάνει φοβερή εκμετάλευση των dymamic views (DMV)

  • sys.dm_db_missing_index_group_stats,
  • sys.dm_db_missing_index_groups,
  • sys.dm_db_missing_index_details.

Θα σας συνιστούσα να διαβάσετε το documentation στα BOL του SQL Server γιατί έχουν κάποιες "ιδιοτροπίες" οι συγκεκριμένες DMV.

Επίσης παράγει και το script για την δημιουργία του index ;).

Enjoy it.

Code Snippet
  1. SELECT  
  2. sys.objects.name,
  3. (avg_total_user_cost * avg_user_impact) * (user_seeks + user_scans) as Impact,  
  4. cast('CREATE NONCLUSTERED INDEX ~NewNameHere~ ON ' + sys.objects.name
  5. + ' ( ' + mid.equality_columns +
  6. CASE WHEN mid.inequality_columns IS NULL THEN '' ELSE
  7. CASE WHEN mid.equality_columns IS NULL THEN ''
  8. ELSE ',' END +     mid.inequality_columns END + ' ) ' +
  9. CASE WHEN mid.included_columns IS NULL THEN ''
  10. ELSE 'INCLUDE (' + mid.included_columns + ')' END + ';' as xml) AS CreateIndexStatement,
  11. mid.equality_columns, mid.inequality_columns, mid.included_columns
  12. FROM sys.dm_db_missing_index_group_stats AS migs
  13.     INNER JOIN sys.dm_db_missing_index_groups AS mig ON migs.group_handle = mig.index_group_handle
  14.     INNER JOIN sys.dm_db_missing_index_details AS mid ON mig.index_handle = mid.index_handle
  15.     INNER JOIN sys.objects WITH (nolock) ON mid.object_id = sys.objects.object_id
  16. WHERE (migs.group_handle IN(SELECT TOP (500) group_handle
  17.                             FROM sys.dm_db_missing_index_group_stats WITH (nolock)
  18.                             ORDER BY (avg_total_user_cost * avg_user_impact) * (user_seeks + user_scans) DESC))
  19. ORDER BY 2 DESC

Antonios Chatzipavlis

Antonios Chatzipavlis

Antonios Chatzipavlis is a highly experienced Data Solutions Consultant and Trainer. He has been working in the IT industry since 1988, holding various roles such as senior developer, IT Manager, Data & AI Solutions Architect and Consultant.

Since 1995, Antonios has focused on modern technologies and software development tools, primarily by Microsoft. He has specialized in Data & AI since 2000, with expertise in Microsoft Data Platform (SQL Server, Azure SQL Databases, Azure Synapse Analytics, Microsoft Fabric, Power BI, AI) and Databricks.

Antonios is also a Microsoft Certified Trainer (MCT) for over 25 years, has been recognized as a Microsoft Most Valuable Professional (MVP) in Data Platform since 2010 and he is in the Data Expert 40 Powerlist 2024 by Boussias. He is the co-founder and visionary behind XLYTiCA, a company dedicated to Data & AI solutions.

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