Tables without a Clustered Index

Yesterday while adding some new logic to an existing process I noticed an unacceptable level of performance degradation with the routine.  Investigation led me to find that a new table had slipped through the net and been created without a clustered index.  Needless to say adding a clustered index and rebuilding the non-clustered indexes on the table improved the performance of the routine significantly.

Being a DBA, this got me thinking about how this had slipped through the net, how I could prevent it in future and equally as important how many other existing tables didn't have a Clustered Index?  I knocked together the below script which will create a SQL Job that is scheduled to run every Monday at 07:07 and email an operator if there are any tables without a clustered index in all user databases.

There are a few things that will need changing;

·         @notify_email_operator_name=N'Chris'

·         SET @EmailProfile = ''Chris''

·         SET @EmailRecipient = ''Chris@SQLServer365.co.uk''

You can also obviously change the schedule accordingly to suit your needs.

I would be interested to know the results on your servers, leave me a comment with the email subject text from the resulting email.

/*

      -----------------------------------------------------------------

      Find tables without a clustered index

      -----------------------------------------------------------------

    

      For more SQL resources, check out SQLServer365.blogspot.co.uk

      -----------------------------------------------------------------

      You may alter this code for your own purposes.

      You may republish altered code as long as you give due credit.

      You must obtain prior permission before blogging this code.

      THIS CODE AND INFORMATION ARE PROVIDED "AS IS"

    

      -----------------------------------------------------------------

*/

-- Set database context

USE [msdb]

GO

IF  EXISTS (SELECT job_id FROM msdb.dbo.sysjobs_view WHERE name = N'Alert - TablesWithoutClusteredIndex')

EXEC msdb.dbo.sp_delete_job @job_name = N'Alert - TablesWithoutClusteredIndex', @delete_unused_schedule=1

GO

BEGIN TRANSACTION

DECLARE @ReturnCode INT

SELECT @ReturnCode = 0

IF NOT EXISTS (SELECT name FROM msdb.dbo.syscategories WHERE name=N'[Uncategorized (Local)]' AND category_class=1)

BEGIN

EXEC @ReturnCode = msdb.dbo.sp_add_category @class=N'JOB', @type=N'LOCAL', @name=N'[Uncategorized (Local)]'

IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback

END

DECLARE @jobId BINARY(16)

EXEC @ReturnCode =  msdb.dbo.sp_add_job @job_name=N'Alert - TablesWithoutClusteredIndex',

            @enabled=1,

            @notify_level_eventlog=0,

            @notify_level_email=2,

            @notify_level_netsend=0,

            @notify_level_page=0,

            @delete_level=0,

            @description=N'This job runs on a Monday morning at 07:07 and will email if there are any tables without a clustered index in any user database.',

            @category_name=N'[Uncategorized (Local)]',

            @owner_login_name=N'sa', @notify_email_operator_name=N'Chris', @job_id = @jobId OUTPUT

IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback

/****** Object:  Step [Find tables Without a Clustered Index]    Script Date: 11/29/2012 12:20:42 ******/

EXEC @ReturnCode = msdb.dbo.sp_add_jobstep @job_id=@jobId, @step_name=N'Find tables Without a Clustered Index',

            @step_id=1,

            @cmdexec_success_code=0,

            @on_success_action=1,

            @on_success_step_id=0,

            @on_fail_action=2,

            @on_fail_step_id=0,

            @retry_attempts=0,

            @retry_interval=0,

            @os_run_priority=0, @subsystem=N'TSQL',

            @command=N'-- Set database context

USE master;

GO

-- Declare variables

DECLARE @EmailProfile VARCHAR(255)

DECLARE @EmailRecipient VARCHAR(255)

DECLARE @EmailSubject VARCHAR(255)

DECLARE @IndexUsageStats INT

DECLARE @TableCount INT

DECLARE @DatabaseCount INT

-- Set variables

SET @EmailProfile = ''Chris''

SET @EmailRecipient = ''Chris.McGowan@SQLServer365.co.uk''

-- Drop temporary table if exists

IF OBJECT_ID(''tempDB.dbo.#NoClusteredIndex'') IS NOT NULL

    DROP TABLE #NoClusteredIndex;

     

-- Create Temporary Table

CREATE TABLE #NoClusteredIndex

    (

      DatabaseName VARCHAR(255) ,

      SchemaName VARCHAR(255) ,

      TableName VARCHAR(1000)

    );

INSERT INTO #NoClusteredIndex

EXEC sp_msforeachdb ''USE [?];

IF ''''?'''' NOT IN (''''master'''', ''''model'''',''''msdb'''', ''''tempdb'''', ''''ReportServer'''', ''''ReportServerTempDB'''', ''''Distribution'''')

BEGIN

SELECT DISTINCT  DB_NAME() AS DatabaseName, SCHEMA_NAME(s.[schema_id]) AS SchemaName, OBJECT_NAME(i.[object_id]) AS TableName

FROM sys.indexes i

INNER JOIN sys.objects o ON o.[object_id] = i.[object_id]

INNER JOIN sys.schemas s ON s.[schema_id] = o.[schema_id]

WHERE i.INDEX_ID = 0

AND OBJECTPROPERTY(i.[object_id],''''IsUserTable'''') = 1

ORDER BY DatabaseName, SchemaName, TableName ASC;

END

''

-- Check for tables without a clustered index

IF EXISTS ( SELECT  1

            FROM #NoClusteredIndex)

    BEGIN

        DECLARE @tableHTML NVARCHAR(MAX); 

        SET @tableHTML = N''<style type="text/css">''

            + N''.h1 {font-family: Arial, verdana;font-size:16px;border:0px;background-color:white;} ''

            + N''.h2 {font-family: Arial, verdana;font-size:12px;border:0px;background-color:white;} ''

            + N''body {font-family: Arial, verdana;} ''

            + N''table{font-size:12px; border-collapse:collapse;border:1px solid black; padding:3px;} ''

            + N''td{background-color:#F1F1F1; border:1px solid black; padding:3px;} ''

            + N''th{background-color:#99CCFF; border:1px solid black; padding:3px;}''

            + N''</style>'' + N''<table border="1">'' + N''<tr>''

            + N''<th>DatabaseName</th>''

            + N''<th>SchemaName</th>''

            + N''<th>TableName</th>''

            + N''</tr>''

            + CAST(( SELECT td = DatabaseName,

                            '''',

                            td = SchemaName,

                            '''',

                            td = TableName,

                            ''''                        

                     FROM   #NoClusteredIndex

                   FOR

                     XML PATH(''tr'') ,

                         TYPE

                   ) AS NVARCHAR(MAX)) + N''</table>''; 

     

            -- Count tables

            SELECT @TableCount = COUNT(1) FROM #NoClusteredIndex;

           

            -- Count tables

            SELECT @DatabaseCount = COUNT(DISTINCT DatabaseName) FROM #NoClusteredIndex;

     

            -- Set subject

            SET @EmailSubject = ''ALERT - '' + CAST(@TableCount AS VARCHAR(100)) +  '' Tables without a Clustered Index on '' + @@SERVERNAME + '' accross '' + CAST(@DatabaseCount AS VARCHAR(100)) + '' databases''

           

            -- Email results 

        EXEC msdb.dbo.sp_send_dbmail @profile_name = @EmailProfile,

            @recipients = @EmailRecipient, @subject = @EmailSubject,

            @body = @tableHTML, @body_format = ''HTML''; 

    END

    GO',

            @database_name=N'master',

            @flags=12

IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback

EXEC @ReturnCode = msdb.dbo.sp_update_job @job_id = @jobId, @start_step_id = 1

IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback

EXEC @ReturnCode = msdb.dbo.sp_add_jobschedule @job_id=@jobId, @name=N'(07:07) Monday',

            @enabled=1,

            @freq_type=8,

            @freq_interval=2,

            @freq_subday_type=1,

            @freq_subday_interval=0,

            @freq_relative_interval=0,

            @freq_recurrence_factor=1,

            @active_start_date=20121129,

            @active_end_date=99991231,

            @active_start_time=70700,

            @active_end_time=235959

IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback

EXEC @ReturnCode = msdb.dbo.sp_add_jobserver @job_id = @jobId, @server_name = N'(local)'

IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback

COMMIT TRANSACTION

GOTO EndSave

QuitWithRollback:

    IF (@@TRANCOUNT > 0) ROLLBACK TRANSACTION

EndSave:

GO

Enjoy!

Chris