验证此 TSQL 以查找碎片化超过 50% 的索引

Question

select 
OBJECT_SCHEMA_NAME(IPS.object_id) 'schema',
  OBJECT_NAME(IPS.object_id) as table_name,index_type_desc,
  round(avg_fragmentation_in_percent,2) 'avg_fragmentation_in_percent',
  si.name
   from  sys.dm_db_index_physical_stats(db_id(DB_NAME()),null, 
   NULL, NULL , 'DETAILED') AS IPS inner join  sys.indexes si on 
   si.object_id=IPS.object_id
   where
   index_type_desc <> 'HEAP' and avg_fragmentation_in_percent >=50
   order by avg_fragmentation_in_percent desc

Answer 1

Your query has most of the main elements, but you are missing the important index_id join predicate from sys.dm_db_index_physical_stats to sys.indexes:

AND si.index_id = IPS.index_id

You might like to compare your query to the similar one in Glenn Berry's Diagnostic Information Queries for SQL Server 2008:

-- Get fragmentation info for all indexes above a certain size in the current database
--(Query 55) (Index Fragmentation)
-- Note: This query could take some time on a very large database
SELECT 
    DB_NAME(ps.database_id) AS [Database Name], 
    OBJECT_NAME(ps.OBJECT_ID) AS [Object Name], 
    i.name AS [Index Name], 
    ps.index_id, 
    ps.index_type_desc, 
    ps.avg_fragmentation_in_percent, 
    ps.fragment_count, 
    ps.page_count, 
    i.fill_factor, 
    i.has_filter, 
    i.filter_definition
FROM sys.dm_db_index_physical_stats(DB_ID(),NULL, NULL, NULL , N'LIMITED') AS ps
INNER JOIN sys.indexes AS i WITH (NOLOCK)
    ON ps.[object_id] = i.[object_id] 
    AND ps.index_id = i.index_id
WHERE 
    ps.database_id = DB_ID()
    AND ps.page_count > 2500
ORDER BY 
    ps.avg_fragmentation_in_percent DESC 
OPTION (RECOMPILE);

In particular, you might want to limit the minimum page count because it is rarely worth worrying about small structures. Ideally, you would incorporate the features from both queries that suit your purposes.

Required attribution for the code above:

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