declare @Fragmentation float=15;
declare @MinIndexSize bigint=768;
declare @MaxIndexSize bigint=1048576;
declare @PreDescribeSize bigint=32768;

SET NOCOUNT ON
SET ARITHABORT ON
SET NUMERIC_ROUNDABORT OFF

IF OBJECT_ID('tempdb.dbo.#AllocationUnits') IS NOT NULL
    DROP TABLE #AllocationUnits

CREATE TABLE #AllocationUnits (
      ContainerID   BIGINT PRIMARY KEY
    , ReservedPages BIGINT NOT NULL
    , UsedPages     BIGINT NOT NULL
)

INSERT INTO #AllocationUnits (ContainerID, ReservedPages, UsedPages)
SELECT [container_id]
     , SUM([total_pages])
     , SUM([used_pages])
FROM sys.allocation_units WITH(NOLOCK)
GROUP BY [container_id]
HAVING SUM([total_pages]) BETWEEN @MinIndexSize AND @MaxIndexSize

IF OBJECT_ID('tempdb.dbo.#ExcludeList') IS NOT NULL
    DROP TABLE #ExcludeList

CREATE TABLE #ExcludeList (ID INT PRIMARY KEY)

INSERT INTO #ExcludeList
SELECT [object_id]
FROM sys.objects WITH(NOLOCK)
WHERE [type] IN ('V', 'U')
    AND ( [is_ms_shipped] = 1 )

IF OBJECT_ID('tempdb.dbo.#Partitions') IS NOT NULL
    DROP TABLE #Partitions

SELECT [object_id]
     , [index_id]
     , [partition_id]
     , [partition_number]
     , [rows]
     , [data_compression]
INTO #Partitions
FROM sys.partitions WITH(NOLOCK)
WHERE [object_id] > 255
    AND [rows] > 0
    AND [object_id] NOT IN (SELECT * FROM #ExcludeList)

IF OBJECT_ID('tempdb.dbo.#Indexes') IS NOT NULL
    DROP TABLE #Indexes

CREATE TABLE #Indexes (
      ObjectID         INT NOT NULL
    , IndexID          INT NOT NULL
    , IndexName        SYSNAME NULL
    , PagesCount       BIGINT NOT NULL
    , UnusedPagesCount BIGINT NOT NULL
    , PartitionNumber  INT NOT NULL
    , RowsCount        BIGINT NOT NULL
    , IndexType        TINYINT NOT NULL
    , IsAllowPageLocks BIT NOT NULL
    , DataSpaceID      INT NOT NULL
    , DataCompression  TINYINT NOT NULL
    , IsUnique         BIT NOT NULL
    , IsPK             BIT NOT NULL
    , FillFactorValue  INT NOT NULL
    , IsFiltered       BIT NOT NULL
    , PRIMARY KEY (ObjectID, IndexID, PartitionNumber)
)

INSERT INTO #Indexes
SELECT ObjectID         = i.[object_id]
     , IndexID          = i.index_id
     , IndexName        = i.[name]
     , PagesCount       = a.ReservedPages
     , UnusedPagesCount = CASE WHEN ABS(a.ReservedPages - a.UsedPages) > 32 THEN a.ReservedPages - a.UsedPages ELSE 0 END
     , PartitionNumber  = p.[partition_number]
     , RowsCount        = ISNULL(p.[rows], 0)
     , IndexType        = i.[type]
     , IsAllowPageLocks = i.[allow_page_locks]
     , DataSpaceID      = i.[data_space_id]
     , DataCompression  = p.[data_compression]
     , IsUnique         = i.[is_unique]
     , IsPK             = i.[is_primary_key]
     , FillFactorValue  = i.[fill_factor]
     , IsFiltered       = i.[has_filter]
FROM #AllocationUnits a
JOIN #Partitions p ON a.ContainerID = p.[partition_id]
JOIN sys.indexes i WITH(NOLOCK) ON i.[object_id] = p.[object_id] AND p.[index_id] = i.[index_id] 
WHERE i.[type] IN (0, 1, 2, 5, 6)
    AND i.[object_id] > 255

DECLARE @files TABLE (ID INT PRIMARY KEY)
INSERT INTO @files
SELECT DISTINCT [data_space_id]
FROM sys.database_files WITH(NOLOCK)
WHERE [state] != 0
    AND [type] = 0

IF @@ROWCOUNT > 0 BEGIN

    DELETE FROM i
    FROM #Indexes i
    LEFT JOIN sys.destination_data_spaces dds WITH(NOLOCK) ON i.DataSpaceID = dds.[partition_scheme_id] AND i.PartitionNumber = dds.[destination_id]
    WHERE ISNULL(dds.[data_space_id], i.DataSpaceID) IN (SELECT * FROM @files)

END


DECLARE @DBID   INT
      , @DBNAME SYSNAME

SET @DBNAME = DB_NAME()
SELECT @DBID = [database_id]
FROM sys.databases WITH(NOLOCK)
WHERE [name] = @DBNAME

IF OBJECT_ID('tempdb.dbo.#Fragmentation') IS NOT NULL
    DROP TABLE #Fragmentation

CREATE TABLE #Fragmentation (
      ObjectID         INT NOT NULL
    , IndexID          INT NOT NULL
    , PartitionNumber  INT NOT NULL
    , Fragmentation    FLOAT NOT NULL
    , PRIMARY KEY (ObjectID, IndexID, PartitionNumber)
)

INSERT INTO #Fragmentation (ObjectID, IndexID, PartitionNumber, Fragmentation)
SELECT i.ObjectID
     , i.IndexID
     , i.PartitionNumber
     , r.[avg_fragmentation_in_percent]
FROM #Indexes i
CROSS APPLY sys.dm_db_index_physical_stats(@DBID, i.ObjectID, i.IndexID, i.PartitionNumber, 'LIMITED') r
WHERE i.PagesCount <= @PreDescribeSize
    AND r.[index_level] = 0
    AND r.[alloc_unit_type_desc] = 'IN_ROW_DATA'
    AND i.IndexType IN (0, 1, 2)

IF OBJECT_ID('tempdb.dbo.#Columns') IS NOT NULL
    DROP TABLE #Columns

CREATE TABLE #Columns (
      ObjectID     INT NOT NULL
    , ColumnID     INT NOT NULL
    , ColumnName   SYSNAME NULL
    , SystemTypeID TINYINT NULL
    , IsSparse     BIT
    , IsColumnSet  BIT
    , MaxLen       INT
    , PRIMARY KEY (ObjectID, ColumnID)
)

INSERT INTO #Columns
SELECT ObjectID     = [object_id]
     , ColumnID     = [column_id]
     , ColumnName   = [name]
     , SystemTypeID = [system_type_id]
     , IsSparse     = [is_sparse]
     , IsColumnSet  = [is_column_set]
     , MaxLen       = [max_length]
FROM sys.columns WITH(NOLOCK)
WHERE [object_id] IN (SELECT DISTINCT i.ObjectID FROM #Indexes i)

IF OBJECT_ID('tempdb.dbo.#IndexColumns') IS NOT NULL
    DROP TABLE #IndexColumns

CREATE TABLE #IndexColumns (
      ObjectID   INT NOT NULL
    , IndexID    INT NOT NULL
    , OrderID    INT NOT NULL
    , ColumnID   INT NOT NULL
    , IsIncluded BIT NOT NULL
    , PRIMARY KEY (ObjectID, IndexID, ColumnID)
)

INSERT INTO #IndexColumns
SELECT ObjectID   = [object_id]
     , IndexID    = [index_id]
     , OrderID    = CASE WHEN [is_included_column] = 0 THEN [key_ordinal] ELSE [index_column_id] END
     , ColumnID   = [column_id]
     , IsIncluded = ISNULL([is_included_column], 0)
FROM sys.index_columns ic WITH(NOLOCK)
WHERE EXISTS(
        SELECT *
        FROM #Indexes i
        WHERE i.ObjectID = ic.[object_id]
            AND i.IndexID = ic.[index_id]
            AND i.IndexType IN (1, 2)
    )

IF OBJECT_ID('tempdb.dbo.#Lob') IS NOT NULL
    DROP TABLE #Lob

CREATE TABLE #Lob (
      ObjectID    INT NOT NULL
    , IndexID     INT NOT NULL
    , IsLobLegacy BIT
    , IsLob       BIT
    , PRIMARY KEY (ObjectID, IndexID)
)

INSERT INTO #Lob (ObjectID, IndexID, IsLobLegacy, IsLob)
SELECT c.ObjectID
     , IndexID     = ISNULL(i.IndexID, 1)
     , IsLobLegacy = MAX(CASE WHEN c.SystemTypeID IN (34, 35, 99) THEN 1 END)
     , IsLob       = 0
FROM #Columns c
LEFT JOIN #IndexColumns i ON c.ObjectID = i.ObjectID AND c.ColumnID = i.ColumnID
WHERE c.SystemTypeID IN (34, 35, 99)
GROUP BY c.ObjectID
       , i.IndexID

IF OBJECT_ID('tempdb.dbo.#Sparse') IS NOT NULL
    DROP TABLE #Sparse

CREATE TABLE #Sparse (ObjectID INT PRIMARY KEY)
INSERT INTO #Sparse
SELECT DISTINCT ObjectID
FROM #Columns
WHERE IsSparse = 1
    OR IsColumnSet = 1

IF OBJECT_ID('tempdb.dbo.#AggColumns') IS NOT NULL
    DROP TABLE #AggColumns

CREATE TABLE #AggColumns (
      ObjectID        INT NOT NULL
    , IndexID         INT NOT NULL
    , IndexColumns    NVARCHAR(MAX)
    , IncludedColumns NVARCHAR(MAX)
    , PRIMARY KEY (ObjectID, IndexID)
)

INSERT INTO #AggColumns
SELECT t.ObjectID
     , t.IndexID
     , IndexColumns = STUFF((
            SELECT ', [' + c.ColumnName + ']'
            FROM #IndexColumns i
            JOIN #Columns c ON i.ObjectID = c.ObjectID AND i.ColumnID = c.ColumnID
            WHERE i.ObjectID = t.ObjectID
                AND i.IndexID = t.IndexID
                AND i.IsIncluded = 0
            ORDER BY i.OrderID
        FOR XML PATH(''), TYPE).value('(./text())[1]', 'NVARCHAR(MAX)'), 1, 2, '')
     , IncludedColumns = STUFF((
            SELECT ', [' + c.ColumnName + ']'
            FROM #IndexColumns i
            JOIN #Columns c ON i.ObjectID = c.ObjectID AND i.ColumnID = c.ColumnID
            WHERE i.ObjectID = t.ObjectID
                AND i.IndexID = t.IndexID
                AND i.IsIncluded = 1
            ORDER BY i.OrderID
        FOR XML PATH(''), TYPE).value('(./text())[1]', 'NVARCHAR(MAX)'), 1, 2, '')
FROM (
    SELECT DISTINCT ObjectID, IndexID
    FROM #Indexes
    WHERE IndexType IN (1, 2)
) t

SELECT i.ObjectID
     , i.IndexID
     , i.IndexName
     , ObjectName       = o.[name]
     , SchemaName       = s.[name]
     , i.PagesCount
     , i.UnusedPagesCount
     , i.PartitionNumber
     , i.RowsCount
     , i.IndexType
     , i.IsAllowPageLocks
     , u.TotalWrites
     , u.TotalReads
     , u.TotalSeeks
     , u.TotalScans
     , u.TotalLookups
     , u.LastUsage
     , i.DataCompression
     , f.Fragmentation
     , IndexStats       = STATS_DATE(i.ObjectID, i.IndexID)
     , IsLobLegacy      = ISNULL(lob.IsLobLegacy, 0)
     , IsLob            = ISNULL(lob.IsLob, 0)
     , IsSparse         = CAST(CASE WHEN p.ObjectID IS NULL THEN 0 ELSE 1 END AS BIT)
     , IsPartitioned    = CAST(CASE WHEN dds.[data_space_id] IS NOT NULL THEN 1 ELSE 0 END AS BIT)
     , FileGroupName    = fg.[name]
     , i.IsUnique
     , i.IsPK
     , i.FillFactorValue
     , i.IsFiltered
     , a.IndexColumns
     , a.IncludedColumns
FROM #Indexes i
JOIN sys.objects o WITH(NOLOCK) ON o.[object_id] = i.ObjectID
JOIN sys.schemas s WITH(NOLOCK) ON s.[schema_id] = o.[schema_id]
LEFT JOIN #AggColumns a ON a.ObjectID = i.ObjectID AND a.IndexID = i.IndexID
LEFT JOIN #Sparse p ON p.ObjectID = i.ObjectID
LEFT JOIN #Fragmentation f ON f.ObjectID = i.ObjectID AND f.IndexID = i.IndexID AND f.PartitionNumber = i.PartitionNumber
LEFT JOIN (
    SELECT ObjectID      = [object_id]
         , IndexID       = [index_id]
         , TotalWrites   = NULLIF([user_updates], 0)
         , TotalReads    = NULLIF([user_seeks] + [user_scans] + [user_lookups], 0)
         , TotalSeeks    = NULLIF([user_seeks], 0)
         , TotalScans    = NULLIF([user_scans], 0)
         , TotalLookups  = NULLIF([user_lookups], 0)
         , LastUsage     = (
                                SELECT MAX(dt)
                                FROM (
                                    VALUES ([last_user_seek])
                                         , ([last_user_scan])
                                         , ([last_user_lookup])
                                         , ([last_user_update])
                                ) t(dt)
                           )
    FROM sys.dm_db_index_usage_stats WITH(NOLOCK)
    WHERE [database_id] = @DBID
) u ON i.ObjectID = u.ObjectID AND i.IndexID = u.IndexID
LEFT JOIN #Lob lob ON lob.ObjectID = i.ObjectID AND lob.IndexID = i.IndexID
LEFT JOIN sys.destination_data_spaces dds WITH(NOLOCK) ON i.DataSpaceID = dds.[partition_scheme_id] AND i.PartitionNumber = dds.[destination_id]
JOIN sys.filegroups fg WITH(NOLOCK) ON ISNULL(dds.[data_space_id], i.DataSpaceID) = fg.[data_space_id] 
WHERE o.[type] IN ('V', 'U')
    AND (
            f.Fragmentation >= @Fragmentation
        OR
            i.PagesCount > @PreDescribeSize
        OR
            i.IndexType IN (5, 6)
    )