functions/Set-DbaDbCompression.ps1

function Set-DbaDbCompression {
<#
    .SYNOPSIS
        Sets tables and indexes with preferred compression setting.
 
     .DESCRIPTION
        This function set the appropriate compression recommendation.
        Remember Uptime is critical, the longer uptime, the more accurate the analysis is.
        You would probably be best if you utilized Get-DbaUptime first, before running this command.
         
        Set-DbaDbCompression script derived from GitHub and the tigertoolbox
        (https://github.com/Microsoft/tigertoolbox/tree/master/Evaluate-Compression-Gains)
     
    .PARAMETER SqlInstance
        SQL Server name or SMO object representing the SQL Server to connect to. This can be a collection and receive pipeline input to allow the function to be executed against multiple SQL Server instances.
     
    .PARAMETER SqlCredential
        SqlCredential object to connect as. If not specified, current Windows login will be used.
     
    .PARAMETER Database
        The database(s) to process - this list is autopopulated from the server. If unspecified, all databases will be processed.
     
    .PARAMETER ExcludeDatabase
        The database(s) to exclude - this list is autopopulated from the server
     
    .PARAMETER MaxRunTime
            Will continue to Alter tables and indexes for the given amount of minutes.
 
    .PARAMETER PercentCompression
            Will only work on the tables/indexes that have the calculated savings at and higher for the given number provided.
     
    .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
        Author: Jason Squires (@js_0505, jstexasdba@gmail.com)
        Tags: Compression, Table, Database
        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/Set-DbaDbCompression
     
    .EXAMPLE
        Set-DbaDbCompression -SqlInstance localhost -MaxRunTime 60 -PercentCompression 25
        Set the compression run time to 60 minutes and will start the compression of tables/indexes
        that have a difference of 25% or higher between current and recommended.
     
    .EXAMPLE
        Set-DbaDbCompression -SqlInstance ServerA -Database DBName -MaxRunTime 60 -PercentCompression 25 | Out-GridView
        Set the compression run time to 60 minutes and will start the compression of tables/indexes
        that have a difference of 25% or higher between current and recommended and the results into a nicely formated GridView.
     
    .EXAMPLE
        $cred = Get-Credential sqladmin
        Set-DbaDbCompression -SqlInstance ServerA -ExcludeDatabase Database -SqlCredential $cred -MaxRunTime 60 -PercentCompression 25
        Returns results of all potential compression options for all databases
        with the recommendation of either Page or Row
     
    .EXAMPLE
        $servers = 'Server1','Server2'
        foreach ($svr in $servers)
        {
            Set-DbaDbCompression -SqlInstance $svr -MaxRunTime 60 -PercentCompression 25 | Export-Csv -Path C:\temp\CompressionAnalysisPAC.csv -Append
        }
     
        This produces a full list of all your servers listed and is pushed to a csv for you to analyize.
        Set the compression run time to 60 minutes and will start the compression of tables/indexes; across all listed servers;
        that have a difference of 25% or higher between current and recommended.
#>

    [CmdletBinding(DefaultParameterSetName = "Default")]
    param (
        [parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [Alias("ServerInstance", "SqlServer")]
        [DbaInstanceParameter[]]$SqlInstance,
        [PSCredential]$SqlCredential,
        [object[]]$Database,
        [object[]]$ExcludeDatabase,
        [parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [int]$MaxRunTime,
        [parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [int]$PercentCompression,
        [switch][Alias('Silent')]$EnableException
    )
    
    begin {
        Write-Message -Level System -Message "Bound parameters: $($PSBoundParameters.Keys -join ", ")"
        $sql = "SET NOCOUNT ON;
                IF OBJECT_ID('tempdb..##setdbacompression' , 'U') IS NOT NULL
                DROP TABLE ##setdbacompression
                 
                IF OBJECT_ID('tempdb..##tmpEstimateRow' , 'U') IS NOT NULL
                DROP TABLE ##tmpEstimateRow
                IF OBJECT_ID('tempdb..##tmpEstimatePage' , 'U') IS NOT NULL
                DROP TABLE ##tmpEstimatePage
                DECLARE @MaxRunTimeInMinutes INT = $MaxRunTime
                DECLARE @PercentCompressed INT = $PercentCompression
                DECLARE @CompressedCount INT;
                SET @CompressedCount = 0;
                DECLARE @StartTime DATETIME2;
                SET @StartTime = CURRENT_TIMESTAMP;
                CREATE TABLE ##setdbacompression (PK INT IDENTITY NOT NULL PRIMARY KEY
                    ,[Schema] sysname
                    ,[TableName] sysname
                    ,[IndexName] sysname NULL
                    ,[Partition] int
                    ,[IndexID] int
                    ,[IndexType] VARCHAR(12)
                    ,[PercentScan] smallint
                    ,[PercentUpdate] smallint
                    ,[RowEstimatePercentOriginal] bigint
                    ,[PageEstimatePercentOriginal] bigint
                    ,[CompressionTypeRecommendation] VARCHAR(7)
                    ,SizeCurrent bigint
                    ,SizeRequested bigint
                    ,PercentCompression numeric(10,2)
                    ,AlreadyProcessed BIT
                );
                CREATE TABLE ##tmpEstimateRow (
                    objname sysname
                    ,schname sysname
                    ,indid int
                    ,partnr int
                    ,SizeCurrent bigint
                    ,SizeRequested bigint
                    ,SampleCurrent bigint
                    ,SampleRequested bigint
                );
                CREATE TABLE ##tmpEstimatePage (
                    objname sysname
                    ,schname sysname
                    ,indid int
                    ,partnr int
                    ,SizeCurrent bigint
                    ,SizeRequested bigint
                    ,SampleCurrent bigint
                    ,SampleRequested bigint
                );
                INSERT INTO ##setdbacompression
                ([Schema]
                ,[TableName]
                ,[IndexName]
                ,[Partition]
                ,[IndexID]
                ,[IndexType]
                ,[PercentScan]
                ,[PercentUpdate]
                ,[AlreadyProcessed]
                )
                SELECT s.name AS [Schema], o.name AS [TableName], x.name AS [IndexName],
                       i.partition_number AS [Partition], i.Index_ID AS [IndexID], x.type_desc AS [IndexType],
                       i.range_scan_count * 100.0 / (i.range_scan_count + i.leaf_insert_count + i.leaf_delete_count + i.leaf_update_count + i.leaf_page_merge_count + i.singleton_lookup_count) AS [PercentScan],
                       i.leaf_update_count * 100.0 / (i.range_scan_count + i.leaf_insert_count + i.leaf_delete_count + i.leaf_update_count + i.leaf_page_merge_count + i.singleton_lookup_count) AS [PercentUpdate], 0 as AlreadyProcessed
                FROM sys.dm_db_index_operational_stats (db_id(), NULL, NULL, NULL) i
                    INNER JOIN sys.objects o ON o.object_id = i.object_id
                    INNER JOIN sys.schemas s ON o.schema_id = s.schema_id
                    INNER JOIN sys.indexes x ON x.object_id = i.object_id AND x.Index_ID = i.Index_ID
                    INNER JOIN sys.partitions p on x.object_id = p.object_id and x.Index_ID = p.Index_ID
                WHERE (i.range_scan_count + i.leaf_insert_count + i.leaf_delete_count + leaf_update_count + i.leaf_page_merge_count + i.singleton_lookup_count) <> 0
                    AND objectproperty(i.object_id,'IsUserTable') = 1 and p.data_compression_desc = 'NONE' and p.rows>0
                ORDER BY [TableName] ASC;
                DECLARE @schema sysname, @tbname sysname, @ixid int
                DECLARE cur CURSOR FAST_FORWARD FOR SELECT [Schema], [TableName], [IndexID] FROM ##setdbacompression
                OPEN cur
                FETCH NEXT FROM cur INTO @schema, @tbname, @ixid
                WHILE @@FETCH_STATUS = 0
                BEGIN
                    DECLARE @sqlcmd NVARCHAR(500)
                    SET @sqlcmd = 'EXEC sp_estimate_data_compression_savings ''' + @schema + ''', ''' + @tbname + ''', ''' + cast(@ixid as varchar)+ ''', NULL, ''ROW''';
                    INSERT INTO ##tmpEstimateRow
                    (objname
                    ,schname
                    ,indid
                    ,partnr
                    ,SizeCurrent
                    ,SizeRequested
                    ,SampleCurrent
                    ,SampleRequested
                    )
                    EXECUTE sp_executesql @sqlcmd
                     
                    SET @sqlcmd = 'EXEC sp_estimate_data_compression_savings ''' + @schema + ''', ''' + @tbname + ''', ''' + cast(@ixid as varchar)+ ''', NULL, ''PAGE''';
                    INSERT INTO ##tmpEstimatePage
                    (objname
                    ,schname
                    ,indid
                    ,partnr
                    ,SizeCurrent
                    ,SizeRequested
                    ,SampleCurrent
                    ,SampleRequested
                    )
                    EXECUTE sp_executesql @sqlcmd
                    FETCH NEXT FROM cur INTO @schema, @tbname, @ixid
                END
                CLOSE cur
                DEALLOCATE cur;
                WITH tmp_cte (objname, schname, indid, pct_of_orig_row, pct_of_orig_page, SizeCurrent,SizeRequested)
                     AS (SELECT tr.objname,
                                tr.schname,
                                tr.indid,
                                ( tr.SampleRequested * 100 ) / CASE
                                                            WHEN tr.SampleCurrent = 0 THEN 1
                                                            ELSE tr.SampleCurrent
                                                          END AS pct_of_orig_row,
                                ( tp.SampleRequested * 100 ) / CASE
                                                            WHEN tp.SampleCurrent = 0 THEN 1
                                                            ELSE tp.SampleCurrent
                                                          END AS pct_of_orig_page,
                                tr.SizeCurrent,
                                tr.SizeRequested
                         FROM ##tmpestimaterow tr
                                INNER JOIN ##tmpestimatepage tp
                                        ON tr.objname = tp.objname
                                           AND tr.schname = tp.schname
                                           AND tr.indid = tp.indid
                                           AND tr.partnr = tp.partnr)
                UPDATE ##setdbacompression
                SET [RowEstimatePercentOriginal] = tcte.pct_of_orig_row,
                       [PageEstimatePercentOriginal] = tcte.pct_of_orig_page,
                       SizeCurrent=tcte.SizeCurrent,
                       SizeRequested=tcte.SizeRequested
                FROM tmp_cte tcte,
                       ##setdbacompression tcomp
                WHERE tcte.objname = tcomp.TableName
                       AND tcte.schname = tcomp.[schema]
                       AND tcte.indid = tcomp.IndexID;
                WITH tmp_cte2 (TableName, [schema], IndexID, [CompressionTypeRecommendation]
                     )
                     AS (SELECT TableName,
                                [schema],
                                IndexID,
                                CASE
                                  WHEN [RowEstimatePercentOriginal] >= 100
                                       AND [PageEstimatePercentOriginal] >= 100 THEN 'NO_GAIN'
                                  WHEN [PercentUpdate] >= 10 THEN 'ROW'
                                  WHEN [PercentScan] <= 1
                                       AND [PercentUpdate] <= 1
                                       AND [RowEstimatePercentOriginal] <
                                           [PageEstimatePercentOriginal]
                                THEN
                                  'ROW'
                                  WHEN [PercentScan] <= 1
                                       AND [PercentUpdate] <= 1
                                       AND [RowEstimatePercentOriginal] >
                                           [PageEstimatePercentOriginal]
                                THEN
                                  'PAGE'
                                  WHEN [PercentScan] >= 60
                                       AND [PercentUpdate] <= 5 THEN 'PAGE'
                                  WHEN [PercentScan] <= 35
                                       AND [PercentUpdate] <= 5 THEN 'NONE'
                                  ELSE 'ROW'
                                END
                         FROM ##setdbacompression)
                UPDATE ##setdbacompression
                SET [CompressionTypeRecommendation] =
                       tcte2.[CompressionTypeRecommendation]
                FROM tmp_cte2 tcte2,
                       ##setdbacompression tcomp2
                WHERE tcte2.TableName = tcomp2.TableName
                       AND tcte2.[schema] = tcomp2.[schema]
                       AND tcte2.IndexID = tcomp2.IndexID;
                UPDATE ##setdbacompression
                set PercentCompression = 100 -(cast([SizeRequested] as numeric(38,2)) * 100/([SizeCurrent]-ABS(SIGN([SizeCurrent]))+1))
                from ##setdbacompression
                SET NOCOUNT ON;
                DECLARE @UpTime VARCHAR(12), @StartDate DATETIME, @sqlmajorver int, @params NVARCHAR(500)
                SELECT @sqlmajorver = CONVERT(int, (@@microsoftversion / 0x1000000) & 0xff);
                IF @sqlmajorver = 9
                BEGIN
                    SET @sqlcmd = N'SELECT @StartDateOUT = login_time, @UpTimeOUT = DATEDIFF(mi, login_time, GETDATE()) FROM master..sysprocesses WHERE spid = 1';
                END
                ELSE
                BEGIN
                    SET @sqlcmd = N'SELECT @StartDateOUT = sqlserver_start_time, @UpTimeOUT = DATEDIFF(mi,sqlserver_start_time,GETDATE()) FROM sys.dm_os_sys_info';
                END
                SET @params = N'@StartDateOUT DATETIME OUTPUT, @UpTimeOUT VARCHAR(12) OUTPUT';
                EXECUTE sp_executesql @sqlcmd, @params, @StartDateOUT=@StartDate OUTPUT, @UpTimeOUT=@UpTime OUTPUT;
                DECLARE @PK INT
                ,@TableName VARCHAR(150)
                ,@DAD VARCHAR(25)
                ,@Partition INT
                ,@indexID INT
                ,@IndexName VARCHAR(250)
                ,@SQL NVARCHAR(MAX)
                ,@IndexType VARCHAR(50)
                ,@CompressionTypeRecommendation VARCHAR(10);
             -- set the compression
                  DECLARE cCompress CURSOR FAST_FORWARD
                  FOR
                          SELECT [Schema]
                                   ,TableName
                                   ,Partition
                                   ,IndexName
                                   ,IndexType
                                   ,CompressionTypeRecommendation
                                   ,PK
                          FROM ##setdbacompression
                          WHERE CompressionTypeRecommendation <> 'NONE'
                                and AlreadyProcessed=0
                                and PercentCompression >=@PercentCompressed
                          ORDER BY SizeRequested ASC; /* start with smallest tables first */
                  OPEN cCompress
                  FETCH cCompress INTO @Schema, @TableName, @Partition, @IndexName, @IndexType,
                        @CompressionTypeRecommendation, @PK -- prime the cursor;
                  WHILE @@Fetch_Status = 0
                        BEGIN
                              IF @IndexType = 'Clustered'
                                 OR @IndexType = 'heap'
                                 SET @SQL = 'ALTER TABLE ' + @Schema + '.' + @TableName
                                     + ' Rebuild with (data_compression = '
                                     + @CompressionTypeRecommendation + ', SORT_IN_TEMPDB=ON)';
                              ELSE
                                 SET @SQL = 'ALTER INDEX ' + @IndexName + ' on ' + @Schema
                                     + '.' + @TableName
                                     + ' Rebuild with (data_compression = '
                                     + @CompressionTypeRecommendation + ',SORT_IN_TEMPDB=ON)';
                              IF DATEDIFF(mi, @StartTime, CURRENT_TIMESTAMP) < @MaxRunTimeInMinutes
                                 BEGIN
                                    PRINT 'Compressing table/index: '
                                    + @Schema + '.' + @TableName;
                                    EXEC sp_executesql
                                    @SQL;
                                    Update ##setdbacompression
                                    SET AlreadyProcessed = 1
                                    WHERE PK = @PK;
                                    SET @CompressedCount = @CompressedCount
                                    + 1;
                                 END
                              ELSE
                                 BEGIN
                                       PRINT 'Max runtime reached. Some compression performed. Exiting...';
                                       BREAK
                                 END
                              FETCH cCompress INTO @Schema, @TableName, @Partition, @IndexName,
                                    @IndexType, @CompressionTypeRecommendation, @PK;
                        END
                  CLOSE cCompress;
                  DEALLOCATE cCompress;
                  SELECT
                   PK
                  ,DBName = DB_Name()
                  ,[Schema]
                  ,[TableName]
                  ,[IndexName]
                  ,[Partition]
                  ,[IndexID]
                  ,[IndexType]
                  ,[PercentScan]
                  ,[PercentUpdate]
                  ,[RowEstimatePercentOriginal]
                  ,[PageEstimatePercentOriginal]
                  ,[CompressionTypeRecommendation]
                  ,SizeCurrentKB = [SizeCurrent]
                  ,SizeRequestedKB = [SizeRequested]
                  ,PercentCompression
                  ,AlreadyProcessed
                  FROM ##setdbacompression
                  WHERE AlreadyProcessed=1;
                  IF OBJECT_ID('tempdb..##setdbacompression' , 'U') IS NOT NULL
                  DROP TABLE ##setdbacompression
                 
                  IF OBJECT_ID('tempdb..##tmpEstimateRow' , 'U') IS NOT NULL
                  DROP TABLE ##tmpEstimateRow
                  IF OBJECT_ID('tempdb..##tmpEstimatePage' , 'U') IS NOT NULL
                  DROP TABLE ##tmpEstimatePage;"

    }
    
    process {
        
        foreach ($instance in $SqlInstance) {
            try {
                Write-Message -Level VeryVerbose -Message "Connecting to $instance" -Target $instance
                $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $SourceSqlCredential -MinimumVersion 10
            }
            catch {
                Stop-Function -Message "Failed to process Instance $Instance" -ErrorRecord $_ -Target $instance -Continue
            }
            
            $Server.ConnectionContext.StatementTimeout = 0
            
            #The reason why we do this is because of SQL 2016 and they now allow for compression on standard edition.
            if ($Server.EngineEdition -notmatch 'Enterprise' -and $Server.VersionMajor -lt '13') {
                Stop-Function -Message "Only SQL Server Enterprise Edition supports compression on $Server" -Target $Server -Continue
            }
            #If IncludeSystemDBs is true, include systemdbs
            #look at all databases, online/offline/accessible/inaccessible and tell user if a db can't be queried.
            try {
                $dbs = $server.Databases
                if ($Database) {
                    $dbs = $dbs | Where-Object { $Database -contains $_.Name -and $_.IsAccessible -and $_.IsSystemObject -EQ 0 }
                }
                
                else {
                    $dbs = $dbs | Where-Object { $_.IsAccessible -and $_.IsSystemObject -EQ 0 }
                }
                
                if (Test-Bound "ExcludeDatabase") {
                    $dbs = $dbs | Where-Object Name -NotIn $ExcludeDatabase
                }
            }
            catch {
                Stop-Function -Message "Unable to gather list of databases for $instance" -Target $instance -ErrorRecord $_ -Continue
            }
            
            
            foreach ($db in $dbs) {
                try {
                    Write-Message -Level Verbose -Message "Querying $instance - $db"
                    if ($db.status -ne 'Normal' -or $db.IsAccessible -eq $false) {
                        Write-Message -Level Warning -Message "$db is not accessible." -Target $db
                        
                        continue
                    }
                    if ($db.CompatibilityLevel -lt 'Version100') {
                        Stop-Function -Message "$db has a compatibility level lower than Version100 and will be skipped." -Target $db -Continue
                    }
                    #Execute query against individual database and add to output
                    foreach ($row in ($server.Query($sql, $db.Name))) {
                        [pscustomobject]@{
                            ComputerName  = $server.NetName
                            InstanceName  = $server.ServiceName
                            SqlInstance   = $server.DomainInstanceName
                            Database      = $row.DBName
                            Schema          = $row.Schema
                            TableName      = $row.TableName
                            IndexName      = $row.IndexName
                            Partition      = $row.Partition
                            IndexID          = $row.IndexID
                            IndexType      = $row.IndexType
                            PercentScan   = $row.PercentScan
                            PercentUpdate = $row.PercentUpdate
                            RowEstimatePercentOriginal = $row.RowEstimatePercentOriginal
                            PageEstimatePercentOriginal = $row.PageEstimatePercentOriginal
                            CompressionTypeRecommendation = $row.CompressionTypeRecommendation
                            SizeCurrentKB = $row.SizeCurrentKB
                            SizeRequestedKB = $row.SizeRequestedKB
                            PercentCompression = $row.PercentCompression
                            AlreadyProcesssed = $row.AlreadyProcessed
                        }
                    }
                }
                catch {
                    Stop-Function -Message "Unable to query $instance - $db" -Target $db -ErrorRecord $_ -Continue
                }
            }
        }
    }
}