Michael J. Swart

April 6, 2015

Finding Scalar Aggregate Indexed Views in Your Database

Filed under: Miscelleaneous SQL,SQL Scripts,SQLServerPedia Syndication,Technical Articles — Michael J. Swart @ 10:35 am

Fellow MVP Paul White recently blogged about a SQL Server bug. His blog post is called An Indexed View Bug with Scalar Aggregates

It’s a really well-written article (as always). After reading it, it’s natural to wonder whether your databases have any such indexed views?

Chances are that you don’t have any. These indexed views aren’t too common, but if you do have indexed views that use scalar aggregates, here’s a query that can help you find them.
The following query finds indexed views without GROUP BY that have exactly one row in any partition.

with IndexedViewIds as
  SELECT [object_id] from sys.indexes
  SELECT [object_id] from sys.views
IndexedViewInfo as 
    OBJECT_SCHEMA_NAME([object_id]) as SchemaName,
    OBJECT_NAME([object_id]) as ViewName,
    OBJECT_DEFINITION([object_id]) as [Definition]
  FROM IndexedViewIds
FROM IndexedViewInfo v
    SELECT * 
    FROM sys.partitions
    WHERE [object_id] = v.[object_id]
    AND [rows] <> 1
  AND v.[definition] NOT LIKE '%GROUP BY%'


The query isn’t perfect. It’s actually possible (but rare) to get false positives here. This query doesn’t look for any aggregate keywords. So look for them in the SELECT list. Also make sure no GROUP BY clause exists.

It’s also possible (but rare) to miss some indexed views when GROUP BY gets mentioned, but not used. For example, if an indexed view definition contains the phrase GROUP BY in a comment, it won’t show up in this list.

(For my curious co-workers, none of our indexed views use scalar aggregates)

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