functions/Get-DbaHelpIndex.ps1

function Get-DbaHelpIndex {
    <#
        .SYNOPSIS
            Returns size, row and configuration information for indexes in databases.
 
        .DESCRIPTION
            This function will return detailed information on indexes (and optionally statistics) for all indexes in a database, or a given index should one be passed along.
            As this uses SQL Server DMVs to access the data it will only work in 2005 and up (sorry folks still running SQL Server 2000).
            For performance reasons certain statistics information will not be returned from SQL Server 2005 if an ObjectName is not provided.
 
            The data includes:
                - ObjectName: the table containing the index
                - IndexType: clustered/non-clustered/columnstore and whether the index is unique/primary key
                - KeyColumns: the key columns of the index
                - IncludeColumns: any include columns in the index
                - FilterDefinition: any filter that may have been used in the index
                - DataCompression: row/page/none depending upon whether or not compression has been used
                - IndexReads: the number of reads of the index since last restart or index rebuild
                - IndexUpdates: the number of writes to the index since last restart or index rebuild
                - SizeKB: the size the index in KB
                - IndexRows: the number of the rows in the index (note filtered indexes will have fewer rows than exist in the table)
                - IndexLookups: the number of lookups that have been performed (only applicable for the heap or clustered index)
                - MostRecentlyUsed: when the index was most recently queried (default to 1900 for when never read)
                - StatsSampleRows: the number of rows queried when the statistics were built/rebuilt (not included in SQL Server 2005 unless ObjectName is specified)
                - StatsRowMods: the number of changes to the statistics since the last rebuild
                - HistogramSteps: the number of steps in the statistics histogram (not included in SQL Server 2005 unless ObjectName is specified)
                - StatsLastUpdated: when the statistics were last rebuilt (not included in SQL Server 2005 unless ObjectName is specified)
 
        .PARAMETER SqlInstance
            SQL Server name or SMO object representing the SQL Server to connect to.
 
        .PARAMETER SqlCredential
            Allows you to login to servers using SQL Logins as opposed to Windows Auth/Integrated/Trusted. To use:
 
            $cred = Get-Credential, then pass $cred variable to this parameter.
 
            Windows Authentication will be used when SqlCredential is not specified. To connect as a different Windows use
 
        .PARAMETER Database
            The database(s) to process. This list is auto-populated from the server. If unspecified, all databases will be processed.
 
        .PARAMETER ExcludeDatabase
            The database(s) to exclude. This list is auto-populated from the server.
 
        .PARAMETER ObjectName
            The name of a table for which you want to obtain the index information. If the two part naming convention for an object is not used it will use the default schema for the executing user. If not passed it will return data on all indexes in a given database.
 
        .PARAMETER IncludeStats
            If this switch is enabled, statistics as well as indexes will be returned in the output (statistics information such as the StatsRowMods will always be returned for indexes).
 
        .PARAMETER IncludeDataTypes
            If this switch is enabled, the output will include the data type of each column that makes up a part of the index definition (key and include columns).
 
        .PARAMETER Raw
            If this switch is enabled, results may be less user-readable but more suitable for processing by other code.
 
        .PARAMETER EnableException
            By default, when something goes wrong we try to catch it, interpret it and give you a friendly warning message.
            This avoids overwhelming you with "sea of red" exceptions, but is inconvenient because it basically disables advanced scripting.
            Using this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch.
             
        .NOTES
            Tags: Indexes
            Author: Nic Cain, https://sirsql.net/
 
            Website: https://dbatools.io
            Copyright: (C) Chrissy LeMaire, clemaire@gmail.com
            License: GNU GPL v3 https://opensource.org/licenses/GPL-3.0
 
        .LINK
            https://dbatools.io/Get-DbaHelpIndex
 
        .EXAMPLE
            Get-DbaHelpIndex -SqlInstance localhost -Database MyDB
 
            Returns information on all indexes on the MyDB database on the localhost.
 
        .EXAMPLE
            Get-DbaHelpIndex -SqlInstance localhost -Database MyDB,MyDB2
 
            Returns information on all indexes on the MyDB & MyDB2 databases.
 
        .EXAMPLE
            Get-DbaHelpIndex -SqlInstance localhost -Database MyDB -ObjectName dbo.Table1
 
            Returns index information on the object dbo.Table1 in the database MyDB.
 
        .EXAMPLE
            Get-DbaHelpIndex -SqlInstance localhost -Database MyDB -ObjectName dbo.Table1 -IncludeStats
 
            Returns information on the indexes and statistics for the table dbo.Table1 in the MyDB database.
 
        .EXAMPLE
            Get-DbaHelpIndex -SqlInstance localhost -Database MyDB -ObjectName dbo.Table1 -IncludeDataTypes
 
            Returns the index information for the table dbo.Table1 in the MyDB database, and includes the data types for the key and include columns.
 
        .EXAMPLE
            Get-DbaHelpIndex -SqlInstance localhost -Database MyDB -ObjectName dbo.Table1 -Raw
 
            Returns the index information for the table dbo.Table1 in the MyDB database, and returns the numerical data without localized separators.
 
        .EXAMPLE
            Get-DbaHelpIndex -SqlInstance localhost -Database MyDB -IncludeStats -Raw
 
            Returns the index information for all indexes in the MyDB database as well as their statistics, and formats the numerical data without localized separators.
    #>

    [CmdletBinding(SupportsShouldProcess = $false)]
    param (
        [parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [Alias("ServerInstance", "SqlServer")]
        [DbaInstanceParameter[]]$SqlInstance,
        [Alias("Credential")]
        [PSCredential]
        $SqlCredential,
        [Alias("Databases")]
        [object[]]$Database,
        [object[]]$ExcludeDatabase,
        [string]$ObjectName,
        [switch]$IncludeStats,
        [switch]$IncludeDataTypes,
        [switch]$Raw,
        [switch][Alias('Silent')]$EnableException
    )

    begin {

        #Add the table predicate to the query
        if (!$ObjectName) {
            $TablePredicate = "DECLARE @TableName NVARCHAR(256);";
        }
        else {
            $TablePredicate = "DECLARE @TableName NVARCHAR(256); SET @TableName = '$ObjectName';";
        }


        #Figure out if we are including stats in the results
        if ($IncludeStats) {
            $IncludeStatsPredicate = "";
        }
        else {
            $IncludeStatsPredicate = "WHERE IndexType != 'STATISTICS'";
        }

        #Data types being returns with the results?
        if ($IncludeDataTypes) {
            $IncludeDataTypesPredicate = 'DECLARE @IncludeDataTypes BIT; SET @IncludeDataTypes = 1';
        }
        else {
            $IncludeDataTypesPredicate = 'DECLARE @IncludeDataTypes BIT; SET @IncludeDataTypes = 0';
        }

        #region SizesQuery
        $SizesQuery = "
            SET NOCOUNT ON;
            SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
 
            $TablePredicate
            $IncludeDataTypesPredicate
            ;
 
        DECLARE @IndexUsageStats TABLE
            (
            object_id INT ,
            index_id INT ,
            user_scans BIGINT ,
            user_seeks BIGINT ,
            user_updates BIGINT ,
            user_lookups BIGINT ,
            last_user_lookup DATETIME2(0) ,
            last_user_scan DATETIME2(0) ,
            last_user_seek DATETIME2(0)
            );
 
        DECLARE @StatsInfo TABLE
            (
            object_id INT ,
            stats_id INT ,
            stats_column_name NVARCHAR(128) ,
            stats_column_id INT ,
            stats_name NVARCHAR(128) ,
            stats_last_updated DATETIME2(0) ,
            stats_sampled_rows BIGINT ,
            rowmods BIGINT ,
            histogramsteps INT ,
            StatsRows BIGINT ,
            FullObjectName NVARCHAR(256)
            );
 
        INSERT INTO @IndexUsageStats
                ( object_id ,
                index_id ,
                user_scans ,
                user_seeks ,
                user_updates ,
                user_lookups ,
                last_user_lookup ,
                last_user_scan ,
                last_user_seek
                )
                SELECT object_id ,
                        index_id ,
                        user_scans ,
                        user_seeks ,
                        user_updates ,
                        user_lookups ,
                        last_user_lookup ,
                        last_user_scan ,
                        last_user_seek
                FROM sys.dm_db_index_usage_stats
                WHERE database_id = DB_ID();
 
        INSERT INTO @StatsInfo
                ( object_id ,
                stats_id ,
                stats_column_name ,
                stats_column_id ,
                stats_name ,
                stats_last_updated ,
                stats_sampled_rows ,
                rowmods ,
                histogramsteps ,
                StatsRows ,
                FullObjectName
                )
                SELECT s.object_id ,
                        s.stats_id ,
                        c.name ,
                        sc.stats_column_id ,
                        s.name ,
                        sp.last_updated ,
                        sp.rows_sampled ,
                        sp.modification_counter ,
                        sp.steps ,
                        sp.rows ,
                        QUOTENAME(sch.name) + '.' + QUOTENAME(t.name) AS FullObjectName
                FROM [sys].[stats] AS [s]
                        INNER JOIN sys.stats_columns sc ON s.stats_id = sc.stats_id
                                                        AND s.object_id = sc.object_id
                        INNER JOIN sys.columns c ON c.object_id = sc.object_id
                                                    AND c.column_id = sc.column_id
                        INNER JOIN sys.tables t ON c.object_id = t.object_id
                        INNER JOIN sys.schemas sch ON sch.schema_id = t.schema_id
                        OUTER APPLY sys.dm_db_stats_properties([s].[object_id],
                                                            [s].[stats_id]) AS [sp]
                WHERE s.object_id = CASE WHEN @TableName IS NULL THEN s.object_id
                                        else OBJECT_ID(@TableName)
                                    END;
 
 
        ;
        WITH cteStatsInfo
                AS ( SELECT object_id ,
                                si.stats_id ,
                                si.stats_name ,
                                STUFF((SELECT N', ' + stats_column_name
                                    FROM @StatsInfo si2
                                    WHERE si2.object_id = si.object_id
                                                AND si2.stats_id = si.stats_id
                                    ORDER BY si2.stats_column_id
                                FOR XML PATH(N'') ,
                                        TYPE).value(N'.[1]', N'nvarchar(1000)'), 1,
                                    2, N'') AS StatsColumns ,
                                MAX(si.stats_sampled_rows) AS SampleRows ,
                                MAX(si.rowmods) AS RowMods ,
                                MAX(si.histogramsteps) AS HistogramSteps ,
                                MAX(si.stats_last_updated) AS StatsLastUpdated ,
                                MAX(si.StatsRows) AS StatsRows,
                                FullObjectName
                    FROM @StatsInfo si
                    GROUP BY si.object_id ,
                                si.stats_id ,
                                si.stats_name ,
                                si.FullObjectName
                    ),
                cteIndexSizes
                AS ( SELECT object_id ,
                                index_id ,
                                CASE WHEN index_id < 2
                                    THEN ( ( SUM(in_row_data_page_count
                                                + lob_used_page_count
                                                + row_overflow_used_page_count)
                                            * 8192 ) / 1024 )
                                    else ( ( SUM(used_page_count) * 8192 ) / 1024 )
                                END AS SizeKB
                    FROM sys.dm_db_partition_stats
                    GROUP BY object_id ,
                                index_id
                    ),
                cteRows
                AS ( SELECT object_id ,
                                index_id ,
                                SUM(rows) AS IndexRows
                    FROM sys.partitions
                    GROUP BY object_id ,
                                index_id
                    ),
                cteIndex
                AS ( SELECT OBJECT_NAME(c.object_id) AS ObjectName ,
                                c.object_id ,
                                c.index_id ,
                                i.name COLLATE SQL_Latin1_General_CP1_CI_AS AS name ,
                                c.index_column_id ,
                                c.column_id ,
                                c.is_included_column ,
                                CASE WHEN @IncludeDataTypes = 0
                                        AND c.is_descending_key = 1
                                    THEN sc.name + ' DESC'
                                    WHEN @IncludeDataTypes = 0
                                        AND c.is_descending_key = 0 THEN sc.name
                                    WHEN @IncludeDataTypes = 1
                                        AND c.is_descending_key = 1
                                        AND c.is_included_column = 0
                                    THEN sc.name + ' DESC (' + t.name + ') '
                                    WHEN @IncludeDataTypes = 1
                                        AND c.is_descending_key = 0
                                        AND c.is_included_column = 0
                                    THEN sc.name + ' (' + t.name + ')'
                                    else sc.name
                                END AS ColumnName ,
                                i.filter_definition ,
                                ISNULL(dd.user_scans, 0) AS user_scans ,
                                ISNULL(dd.user_seeks, 0) AS user_seeks ,
                                ISNULL(dd.user_updates, 0) AS user_updates ,
                                ISNULL(dd.user_lookups, 0) AS user_lookups ,
                                CONVERT(DATETIME2(0), ISNULL(dd.last_user_lookup,
                                                            '1901-01-01')) AS LastLookup ,
                                CONVERT(DATETIME2(0), ISNULL(dd.last_user_scan,
                                                            '1901-01-01')) AS LastScan ,
                                CONVERT(DATETIME2(0), ISNULL(dd.last_user_seek,
                                                            '1901-01-01')) AS LastSeek ,
                                i.fill_factor ,
                                c.is_descending_key ,
                                p.data_compression_desc ,
                                i.type_desc ,
                                i.is_unique ,
                                i.is_unique_constraint ,
                                i.is_primary_key ,
                                ci.SizeKB ,
                                cr.IndexRows ,
                                QUOTENAME(sch.name) + '.' + QUOTENAME(tbl.name) AS FullObjectName
                    FROM sys.indexes i
                                JOIN sys.index_columns c ON i.object_id = c.object_id
                                                            AND i.index_id = c.index_id
                                JOIN sys.columns sc ON c.object_id = sc.object_id
                                                    AND c.column_id = sc.column_id
                                INNER JOIN sys.tables tbl ON c.object_id = tbl.object_id
                                INNER JOIN sys.schemas sch ON sch.schema_id = tbl.schema_id
                                LEFT JOIN sys.types t ON sc.user_type_id = t.user_type_id
                                LEFT JOIN @IndexUsageStats dd ON i.object_id = dd.object_id
                                                                AND i.index_id = dd.index_id --and dd.database_id = db_id()
                                JOIN sys.partitions p ON i.object_id = p.object_id
                                                        AND i.index_id = p.index_id
                                JOIN cteIndexSizes ci ON i.object_id = ci.object_id
                                                        AND i.index_id = ci.index_id
                                JOIN cteRows cr ON i.object_id = cr.object_id
                                                AND i.index_id = cr.index_id
                    WHERE i.object_id = CASE WHEN @TableName IS NULL
                                                THEN i.object_id
                                                else OBJECT_ID(@TableName)
                                            END
                    ),
                cteResults
                AS ( SELECT ci.FullObjectName ,
                                ci.object_id ,
                                MAX(index_id) AS Index_Id ,
                                ci.type_desc
                                + CASE WHEN ci.is_primary_key = 1
                                    THEN ' (PRIMARY KEY)'
                                    WHEN ci.is_unique_constraint = 1
                                    THEN ' (UNIQUE CONSTRAINT)'
                                    WHEN ci.is_unique = 1 THEN ' (UNIQUE)'
                                    else ''
                                END AS IndexType ,
                                name AS IndexName ,
                                STUFF((SELECT N', ' + ColumnName
                                    FROM cteIndex ci2
                                    WHERE ci2.name = ci.name
                                                AND ci2.is_included_column = 0
                                    GROUP BY ci2.index_column_id ,
                                                ci2.ColumnName
                                    ORDER BY ci2.index_column_id
                                FOR XML PATH(N'') ,
                                        TYPE).value(N'.[1]', N'nvarchar(1000)'), 1,
                                    2, N'') AS KeyColumns ,
                                ISNULL(STUFF((SELECT N', ' + ColumnName
                                            FROM cteIndex ci3
                                            WHERE ci3.name = ci.name
                                                        AND ci3.is_included_column = 1
                                            GROUP BY ci3.index_column_id ,
                                                        ci3.ColumnName
                                            ORDER BY ci3.index_column_id
                                    FOR XML PATH(N'') ,
                                                TYPE).value(N'.[1]',
                                                            N'nvarchar(1000)'), 1, 2,
                                            N''), '') AS IncludeColumns ,
                                ISNULL(filter_definition, '') AS FilterDefinition ,
                                ci.fill_factor ,
                                CASE WHEN ci.data_compression_desc = 'NONE' THEN ''
                                    else ci.data_compression_desc
                                END AS DataCompression ,
                                MAX(ci.user_seeks) + MAX(ci.user_scans)
                                + MAX(ci.user_lookups) AS IndexReads ,
                                MAX(ci.user_lookups) AS IndexLookups ,
                                ci.user_updates AS IndexUpdates ,
                                ci.SizeKB AS SizeKB ,
                                ci.IndexRows AS IndexRows ,
                                CASE WHEN LastScan > LastSeek
                                        AND LastScan > LastLookup THEN LastScan
                                    WHEN LastSeek > LastScan
                                        AND LastSeek > LastLookup THEN LastSeek
                                    WHEN LastLookup > LastScan
                                        AND LastLookup > LastSeek THEN LastLookup
                                    else ''
                                END AS MostRecentlyUsed
                    FROM cteIndex ci
                    GROUP BY ci.ObjectName ,
                                ci.name ,
                                ci.filter_definition ,
                                ci.object_id ,
                                ci.LastLookup ,
                                ci.LastSeek ,
                                ci.LastScan ,
                                ci.user_updates ,
                                ci.fill_factor ,
                                ci.data_compression_desc ,
                                ci.type_desc ,
                                ci.is_primary_key ,
                                ci.is_unique ,
                                ci.is_unique_constraint ,
                                ci.SizeKB ,
                                ci.IndexRows ,
                                ci.FullObjectName
                    ),
                AllResults
                AS ( SELECT c.FullObjectName ,
                                ISNULL(IndexType, 'STATISTICS') AS IndexType ,
                                ISNULL(IndexName, si.stats_name) AS IndexName ,
                                ISNULL(KeyColumns, si.StatsColumns) AS KeyColumns ,
                                ISNULL(IncludeColumns, '') AS IncludeColumns ,
                                FilterDefinition ,
                                fill_factor AS [FillFactor] ,
                                DataCompression ,
                                IndexReads ,
                                IndexUpdates ,
                                SizeKB ,
                                IndexRows ,
                                IndexLookups ,
                                MostRecentlyUsed ,
                                SampleRows AS StatsSampleRows ,
                                RowMods AS StatsRowMods ,
                                si.HistogramSteps ,
                                si.StatsLastUpdated ,
                                1 AS Ordering
                    FROM cteResults c
                                INNER JOIN cteStatsInfo si ON si.object_id = c.object_id
                                                            AND si.stats_id = c.Index_Id
                    UNION
                    SELECT QUOTENAME(sch.name) + '.' + QUOTENAME(tbl.name) AS FullObjectName ,
                                'STATISTICS' ,
                                stats_name ,
                                StatsColumns ,
                                '' ,
                                '' AS FilterDefinition ,
                                '' AS Fill_Factor ,
                                '' AS DataCompression ,
                                '' AS IndexReads ,
                                '' AS IndexUpdates ,
                                '' AS SizeKB ,
                                StatsRows AS IndexRows ,
                                '' AS IndexLookups ,
                                '' AS MostRecentlyUsed ,
                                SampleRows AS StatsSampleRows ,
                                RowMods AS StatsRowMods ,
                                csi.HistogramSteps ,
                                csi.StatsLastUpdated ,
                                2
                    FROM cteStatsInfo csi
                    INNER JOIN sys.tables tbl ON csi.object_id = tbl.object_id
                                INNER JOIN sys.schemas sch ON sch.schema_id = tbl.schema_id
                    WHERE stats_id NOT IN (
                                SELECT stats_id
                                FROM cteResults c
                                        INNER JOIN cteStatsInfo si ON si.object_id = c.object_id
                                                                    AND si.stats_id = c.Index_Id )
                    )
            SELECT FullObjectName ,
                    ISNULL(IndexType, 'STATISTICS') AS IndexType ,
                    IndexName ,
                    KeyColumns ,
                    ISNULL(IncludeColumns, '') AS IncludeColumns ,
                    FilterDefinition ,
                    [FillFactor] AS [FillFactor] ,
                    DataCompression ,
                    IndexReads ,
                    IndexUpdates ,
                    SizeKB ,
                    IndexRows ,
                    IndexLookups ,
                    MostRecentlyUsed ,
                    StatsSampleRows ,
                    StatsRowMods ,
                    HistogramSteps ,
                    StatsLastUpdated
            FROM AllResults
                    $IncludeStatsPredicate
        OPTION ( RECOMPILE );
        "

        #endRegion SizesQuery


        #region sizesQuery2005
        $SizesQuery2005 = "
        SET NOCOUNT ON;
        SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
 
        $TablePredicate
        $IncludeDataTypesPredicate
        ;
 
        DECLARE @AllResults TABLE
            (
                RowNum INT ,
                FullObjectName NVARCHAR(300) ,
                IndexType NVARCHAR(256) ,
                IndexName NVARCHAR(256) ,
                KeyColumns NVARCHAR(2000) ,
                IncludeColumns NVARCHAR(2000) ,
                FilterDefinition NVARCHAR(100) ,
                [FillFactor] TINYINT ,
                DataCompression CHAR(4) ,
                IndexReads BIGINT ,
                IndexUpdates BIGINT ,
                SizeKB BIGINT ,
                IndexRows BIGINT ,
                IndexLookups BIGINT ,
                MostRecentlyUsed DATETIME ,
                StatsSampleRows BIGINT ,
                StatsRowMods BIGINT ,
                HistogramSteps INT ,
                StatsLastUpdated DATETIME ,
                object_id BIGINT ,
                index_id BIGINT
            );
 
        DECLARE @IndexUsageStats TABLE
            (
            object_id INT ,
            index_id INT ,
            user_scans BIGINT ,
            user_seeks BIGINT ,
            user_updates BIGINT ,
            user_lookups BIGINT ,
            last_user_lookup DATETIME ,
            last_user_scan DATETIME ,
            last_user_seek DATETIME
            );
 
        DECLARE @StatsInfo TABLE
            (
            object_id INT ,
            stats_id INT ,
            stats_column_name NVARCHAR(128) ,
            stats_column_id INT ,
            stats_name NVARCHAR(128) ,
            stats_last_updated DATETIME ,
            stats_sampled_rows BIGINT ,
            rowmods BIGINT ,
            histogramsteps INT ,
            StatsRows BIGINT ,
            FullObjectName NVARCHAR(256)
            );
 
        INSERT INTO @IndexUsageStats
                ( object_id ,
                index_id ,
                user_scans ,
                user_seeks ,
                user_updates ,
                user_lookups ,
                last_user_lookup ,
                last_user_scan ,
                last_user_seek
                )
                SELECT object_id ,
                        index_id ,
                        user_scans ,
                        user_seeks ,
                        user_updates ,
                        user_lookups ,
                        last_user_lookup ,
                        last_user_scan ,
                        last_user_seek
                FROM sys.dm_db_index_usage_stats
                WHERE database_id = DB_ID();
 
 
        INSERT INTO @StatsInfo
                ( object_id ,
                stats_id ,
                stats_column_name ,
                stats_column_id ,
                stats_name ,
                stats_last_updated ,
                stats_sampled_rows ,
                rowmods ,
                histogramsteps ,
                StatsRows ,
                FullObjectName
                )
                SELECT s.object_id ,
                        s.stats_id ,
                        c.name ,
                        sc.stats_column_id ,
                        s.name ,
                        NULL AS last_updated ,
                        NULL AS rows_sampled ,
                        NULL AS modification_counter ,
                        NULL AS steps ,
                        NULL AS rows ,
                        QUOTENAME(sch.name) + '.' + QUOTENAME(t.name) AS FullObjectName
                FROM [sys].[stats] AS [s]
                        INNER JOIN sys.stats_columns sc ON s.stats_id = sc.stats_id
                                                        AND s.object_id = sc.object_id
                        INNER JOIN sys.columns c ON c.object_id = sc.object_id
                                                    AND c.column_id = sc.column_id
                        INNER JOIN sys.tables t ON c.object_id = t.object_id
                        INNER JOIN sys.schemas sch ON sch.schema_id = t.schema_id
                    -- OUTER APPLY sys.dm_db_stats_properties([s].[object_id],
                    -- [s].[stats_id]) AS [sp]
                WHERE s.object_id = CASE WHEN @TableName IS NULL THEN s.object_id
                                        else OBJECT_ID(@TableName)
                                    END;
 
 
        ;
        WITH cteStatsInfo
                AS ( SELECT object_id ,
                                si.stats_id ,
                                si.stats_name ,
                                STUFF((SELECT N', ' + stats_column_name
                                    FROM @StatsInfo si2
                                    WHERE si2.object_id = si.object_id
                                                AND si2.stats_id = si.stats_id
                                    ORDER BY si2.stats_column_id
                                FOR XML PATH(N'') ,
                                        TYPE).value(N'.[1]', N'nvarchar(1000)'), 1,
                                    2, N'') AS StatsColumns ,
                                MAX(si.stats_sampled_rows) AS SampleRows ,
                                MAX(si.rowmods) AS RowMods ,
                                MAX(si.histogramsteps) AS HistogramSteps ,
                                MAX(si.stats_last_updated) AS StatsLastUpdated ,
                                MAX(si.StatsRows) AS StatsRows,
                                FullObjectName
                    FROM @StatsInfo si
                    GROUP BY si.object_id ,
                                si.stats_id ,
                                si.stats_name ,
                                si.FullObjectName
                    ),
                cteIndexSizes
                AS ( SELECT object_id ,
                                index_id ,
                                CASE WHEN index_id < 2
                                    THEN ( ( SUM(in_row_data_page_count
                                                + lob_used_page_count
                                                + row_overflow_used_page_count)
                                            * 8192 ) / 1024 )
                                    else ( ( SUM(used_page_count) * 8192 ) / 1024 )
                                END AS SizeKB
                    FROM sys.dm_db_partition_stats
                    GROUP BY object_id ,
                                index_id
                    ),
                cteRows
                AS ( SELECT object_id ,
                                index_id ,
                                SUM(rows) AS IndexRows
                    FROM sys.partitions
                    GROUP BY object_id ,
                                index_id
                    ),
                cteIndex
                AS ( SELECT OBJECT_NAME(c.object_id) AS ObjectName ,
                                c.object_id ,
                                c.index_id ,
                                i.name COLLATE SQL_Latin1_General_CP1_CI_AS AS name ,
                                c.index_column_id ,
                                c.column_id ,
                                c.is_included_column ,
                                CASE WHEN @IncludeDataTypes = 0
                                        AND c.is_descending_key = 1
                                    THEN sc.name + ' DESC'
                                    WHEN @IncludeDataTypes = 0
                                        AND c.is_descending_key = 0 THEN sc.name
                                    WHEN @IncludeDataTypes = 1
                                        AND c.is_descending_key = 1
                                        AND c.is_included_column = 0
                                    THEN sc.name + ' DESC (' + t.name + ') '
                                    WHEN @IncludeDataTypes = 1
                                        AND c.is_descending_key = 0
                                        AND c.is_included_column = 0
                                    THEN sc.name + ' (' + t.name + ')'
                                    else sc.name
                                END AS ColumnName ,
                                '' AS filter_definition ,
                                ISNULL(dd.user_scans, 0) AS user_scans ,
                                ISNULL(dd.user_seeks, 0) AS user_seeks ,
                                ISNULL(dd.user_updates, 0) AS user_updates ,
                                ISNULL(dd.user_lookups, 0) AS user_lookups ,
                                CONVERT(DATETIME, ISNULL(dd.last_user_lookup,
                                                            '1901-01-01')) AS LastLookup ,
                                CONVERT(DATETIME, ISNULL(dd.last_user_scan,
                                                            '1901-01-01')) AS LastScan ,
                                CONVERT(DATETIME, ISNULL(dd.last_user_seek,
                                                            '1901-01-01')) AS LastSeek ,
                                i.fill_factor ,
                                c.is_descending_key ,
                                'NONE' as data_compression_desc ,
                                i.type_desc ,
                                i.is_unique ,
                                i.is_unique_constraint ,
                                i.is_primary_key ,
                                ci.SizeKB ,
                                cr.IndexRows ,
                                QUOTENAME(sch.name) + '.' + QUOTENAME(tbl.name) AS FullObjectName
                    FROM sys.indexes i
                                JOIN sys.index_columns c ON i.object_id = c.object_id
                                                            AND i.index_id = c.index_id
                                JOIN sys.columns sc ON c.object_id = sc.object_id
                                                    AND c.column_id = sc.column_id
                                INNER JOIN sys.tables tbl ON c.object_id = tbl.object_id
                                INNER JOIN sys.schemas sch ON sch.schema_id = tbl.schema_id
                                LEFT JOIN sys.types t ON sc.user_type_id = t.user_type_id
                                LEFT JOIN @IndexUsageStats dd ON i.object_id = dd.object_id
                                                                AND i.index_id = dd.index_id --and dd.database_id = db_id()
                                JOIN sys.partitions p ON i.object_id = p.object_id
                                                        AND i.index_id = p.index_id
                                JOIN cteIndexSizes ci ON i.object_id = ci.object_id
                                                        AND i.index_id = ci.index_id
                                JOIN cteRows cr ON i.object_id = cr.object_id
                                                AND i.index_id = cr.index_id
                    WHERE i.object_id = CASE WHEN @TableName IS NULL
                                                THEN i.object_id
                                                else OBJECT_ID(@TableName)
                                            END
                    ),
                cteResults
                AS ( SELECT ci.FullObjectName ,
                                ci.object_id ,
                                MAX(index_id) AS Index_Id ,
                                ci.type_desc
                                + CASE WHEN ci.is_primary_key = 1
                                    THEN ' (PRIMARY KEY)'
                                    WHEN ci.is_unique_constraint = 1
                                    THEN ' (UNIQUE CONSTRAINT)'
                                    WHEN ci.is_unique = 1 THEN ' (UNIQUE)'
                                    else ''
                                END AS IndexType ,
                                name AS IndexName ,
                                STUFF((SELECT N', ' + ColumnName
                                    FROM cteIndex ci2
                                    WHERE ci2.name = ci.name
                                                AND ci2.is_included_column = 0
                                    GROUP BY ci2.index_column_id ,
                                                ci2.ColumnName
                                    ORDER BY ci2.index_column_id
                                FOR XML PATH(N'') ,
                                        TYPE).value(N'.[1]', N'nvarchar(1000)'), 1,
                                    2, N'') AS KeyColumns ,
                                ISNULL(STUFF((SELECT N', ' + ColumnName
                                            FROM cteIndex ci3
                                            WHERE ci3.name = ci.name
                                                        AND ci3.is_included_column = 1
                                            GROUP BY ci3.index_column_id ,
                                                        ci3.ColumnName
                                            ORDER BY ci3.index_column_id
                                    FOR XML PATH(N'') ,
                                                TYPE).value(N'.[1]',
                                                            N'nvarchar(1000)'), 1, 2,
                                            N''), '') AS IncludeColumns ,
                                ISNULL(filter_definition, '') AS FilterDefinition ,
                                ci.fill_factor ,
                                CASE WHEN ci.data_compression_desc = 'NONE' THEN ''
                                    else ci.data_compression_desc
                                END AS DataCompression ,
                                MAX(ci.user_seeks) + MAX(ci.user_scans)
                                + MAX(ci.user_lookups) AS IndexReads ,
                                MAX(ci.user_lookups) AS IndexLookups ,
                                ci.user_updates AS IndexUpdates ,
                                ci.SizeKB AS SizeKB ,
                                ci.IndexRows AS IndexRows ,
                                CASE WHEN LastScan > LastSeek
                                        AND LastScan > LastLookup THEN LastScan
                                    WHEN LastSeek > LastScan
                                        AND LastSeek > LastLookup THEN LastSeek
                                    WHEN LastLookup > LastScan
                                        AND LastLookup > LastSeek THEN LastLookup
                                    else ''
                                END AS MostRecentlyUsed
                    FROM cteIndex ci
                    GROUP BY ci.ObjectName ,
                                ci.name ,
                                ci.filter_definition ,
                                ci.object_id ,
                                ci.LastLookup ,
                                ci.LastSeek ,
                                ci.LastScan ,
                                ci.user_updates ,
                                ci.fill_factor ,
                                ci.data_compression_desc ,
                                ci.type_desc ,
                                ci.is_primary_key ,
                                ci.is_unique ,
                                ci.is_unique_constraint ,
                                ci.SizeKB ,
                                ci.IndexRows ,
                                ci.FullObjectName
                    ), AllResults AS
                        ( SELECT c.FullObjectName ,
                                ISNULL(IndexType, 'STATISTICS') AS IndexType ,
                                ISNULL(IndexName, '') AS IndexName ,
                                ISNULL(KeyColumns, '') AS KeyColumns ,
                                ISNULL(IncludeColumns, '') AS IncludeColumns ,
                                FilterDefinition ,
                                fill_factor AS [FillFactor] ,
                                DataCompression ,
                                IndexReads ,
                                IndexUpdates ,
                                SizeKB ,
                                IndexRows ,
                                IndexLookups ,
                                MostRecentlyUsed ,
                                NULL AS StatsSampleRows ,
                                NULL AS StatsRowMods ,
                                NULL AS HistogramSteps ,
                                NULL AS StatsLastUpdated ,
                                1 AS Ordering ,
                                c.object_id ,
                                c.Index_Id
                    FROM cteResults c
                                INNER JOIN cteStatsInfo si ON si.object_id = c.object_id
                                                            AND si.stats_id = c.Index_Id
                        UNION
                    SELECT QUOTENAME(sch.name) + '.' + QUOTENAME(tbl.name) AS FullObjectName ,
                                'STATISTICS' ,
                                stats_name ,
                                StatsColumns ,
                                '' ,
                                '' AS FilterDefinition ,
                                '' AS Fill_Factor ,
                                '' AS DataCompression ,
                                '' AS IndexReads ,
                                '' AS IndexUpdates ,
                                '' AS SizeKB ,
                                StatsRows AS IndexRows ,
                                '' AS IndexLookups ,
                                '' AS MostRecentlyUsed ,
                                SampleRows AS StatsSampleRows ,
                                RowMods AS StatsRowMods ,
                                csi.HistogramSteps ,
                                csi.StatsLastUpdated ,
                                2 ,
                                csi.object_id ,
                                csi.stats_id
                    FROM cteStatsInfo csi
                    INNER JOIN sys.tables tbl ON csi.object_id = tbl.object_id
                                INNER JOIN sys.schemas sch ON sch.schema_id = tbl.schema_id
                                LEFT JOIN (SELECT si.object_id, si.stats_id
                                            FROM cteResults c
                                            INNER JOIN cteStatsInfo si ON si.object_id = c.object_id
                                                                    AND si.stats_id = c.Index_Id ) AS x on csi.object_id = x.object_id and csi.stats_id = x.stats_id
                        WHERE x.object_id is null
                    )
            INSERT INTO @AllResults
            SELECT row_number() OVER (ORDER BY FullObjectName) AS RowNum ,
                    FullObjectName ,
                    ISNULL(IndexType, 'STATISTICS') AS IndexType ,
                    IndexName ,
                    KeyColumns ,
                    ISNULL(IncludeColumns, '') AS IncludeColumns ,
                    FilterDefinition ,
                    [FillFactor] AS [FillFactor] ,
                    DataCompression ,
                    IndexReads ,
                    IndexUpdates ,
                    SizeKB ,
                    IndexRows ,
                    IndexLookups ,
                    MostRecentlyUsed ,
                    StatsSampleRows ,
                    StatsRowMods ,
                    HistogramSteps ,
                    StatsLastUpdated ,
                    object_id ,
                    index_id
            FROM AllResults
                    $IncludeStatsPredicate
        OPTION ( RECOMPILE );
 
        /* Only update the stats data on 2005 for a single table, otherwise the run time for this is a potential problem for large table/index volumes */
        if @TableName IS NOT NULL
        BEGIN
 
            DECLARE @StatsInfo2005 TABLE (Name nvarchar(128), Updated DATETIME, Rows BIGINT, RowsSampled BIGINT, Steps INT, Density INT, AverageKeyLength INT, StringIndex NVARCHAR(20))
 
            DECLARE @SqlCall NVARCHAR(2000), @RowNum INT;
            SELECT @RowNum = min(RowNum) FROM @AllResults;
            WHILE @RowNum IS NOT NULL
            BEGIN
                SELECT @SqlCall = 'dbcc show_statistics('+FullObjectName+', '+IndexName+') with stat_header' FROM @AllResults WHERE RowNum = @RowNum;
                INSERT INTO @StatsInfo2005 exec (@SqlCall);
                UPDATE @AllResults
                    SET StatsSampleRows = RowsSampled,
                    HistogramSteps = Steps,
                    StatsLastUpdated = Updated
                    FROM @StatsInfo2005
                    WHERE RowNum = @RowNum;
                DELETE FROM @StatsInfo2005
                SELECT @RowNum = min(RowNum) FROM @AllResults WHERE RowNum > @RowNum;
            END;
 
        END;
 
        UPDATE a
        SET a.StatsRowMods = i.rowmodctr
        FROM @AllResults a
            JOIN sys.sysindexes i ON a.object_id = i.id AND a.index_id = i.indid;
 
        SELECT FullObjectName ,
                IndexType ,
                IndexName ,
                KeyColumns ,
                IncludeColumns ,
                FilterDefinition ,
                [FillFactor] ,
                DataCompression ,
                IndexReads ,
                IndexUpdates ,
                SizeKB ,
                IndexRows ,
                IndexLookups ,
                MostRecentlyUsed ,
                StatsSampleRows ,
                StatsRowMods ,
                HistogramSteps ,
                StatsLastUpdated
        FROM @AllResults;"


        #endregion sizesQuery2005
        $server = Connect-SqlInstance -SqlInstance $sqlinstance -SqlCredential $SqlCredential
    }
    process {
        Write-Message -Level Debug -Message $SizesQuery
        Write-Message -Level Debug -Message $SizesQuery2005
        #Need to check the version of SQL
        if ($server.versionMajor -ge 10) {
            $indexesQuery = $SizesQuery
        }

        elseif ($server.Information.Version.Major -eq 9) {
            $indexesQuery = $SizesQuery2005
        }

        else {
            Write-Warning "This function does not support versions lower than SQL Server 2005 (v9)."
            continue
        }

        if ($pipedatabase.Length -gt 0) {
            $databases = $pipedatabase.name
        }

        $databases = $server.Databases
        
        if ($Database) {
            $databases = $databases | Where-Object Name -In $Database
        }

        if ($ExcludeDatabase) {
            $databases = $databases | Where-Object Name -NotIn $ExcludeDatabase
        }

        foreach ($db in $databases) {
            if (!$db.IsAccessible) {
                Write-Message -Level Warning -Message "$db is not accessible. Skipping."
                continue
            }
            try {
                $IndexDetails = ($server.Databases[$db.Name].ExecuteWithResults($indexesQuery)).Tables[0];

                if (!$Raw) {
                    foreach ($detail in $IndexDetails) {
                        $recentlyused = [datetime]$detail.MostRecentlyUsed

                        if ($recentlyused.year -eq 1900) {
                            $recentlyused = $null
                        }

                        [pscustomobject]@{
                            DatabaseName     = $db.Name
                            ObjectName       = $detail.FullObjectName
                            IndexType        = $detail.IndexType
                            KeyColumns       = $detail.KeyColumns
                            IncludeColumns   = $detail.IncludeColumns
                            FilterDefinition = $detail.FilterDefinition
                            DataCompression  = $detail.DataCompression
                            IndexReads       = "{0:N0}" -f $detail.IndexReads
                            IndexUpdates     = "{0:N0}" -f $detail.IndexUpdates
                            SizeKB           = "{0:N0}" -f $detail.SizeKB
                            IndexRows        = "{0:N0}" -f $detail.IndexRows
                            IndexLookups     = "{0:N0}" -f $detail.IndexLookups
                            MostRecentlyUsed = $recentlyused
                            StatsSampleRows  = "{0:N0}" -f $detail.StatsSampleRows
                            StatsRowMods     = "{0:N0}" -f $detail.StatsRowMods
                            HistogramSteps   = $detail.HistogramSteps
                            StatsLastUpdated = $detail.StatsLastUpdated
                        }
                    }
                }

                else {
                    foreach ($detail in $IndexDetails) {
                        $recentlyused = [datetime]$detail.MostRecentlyUsed

                        if ($recentlyused.year -eq 1900) {
                            $recentlyused = $null
                        }

                        [pscustomobject]@{
                            DatabaseName     = $db.Name
                            ObjectName       = $detail.FullObjectName
                            IndexType        = $detail.IndexType
                            KeyColumns       = $detail.KeyColumns
                            IncludeColumns   = $detail.IncludeColumns
                            FilterDefinition = $detail.FilterDefinition
                            DataCompression  = $detail.DataCompression
                            IndexReads       = $detail.IndexReads
                            IndexUpdates     = $detail.IndexUpdates
                            SizeKB           = $detail.SizeKB
                            IndexRows        = $detail.IndexRows
                            IndexLookups     = $detail.IndexLookups
                            MostRecentlyUsed = $recentlyused
                            StatsSampleRows  = $detail.StatsSampleRows
                            StatsRowMods     = $detail.StatsRowMods
                            HistogramSteps   = $detail.HistogramSteps
                            StatsLastUpdated = $detail.StatsLastUpdated
                        }
                    }
                }
            }
            catch {
                Write-Warning "Cannot process $db on $server."
            }
        }
    }
}