Getting important information of SQL Server Backups

Regardless of the method that is used to take SQL Server backups, they need to be carefully monitored 24x7 hours especially in critical database environments whose data is changing rapidly. Keeping the backups up to date is crucial as they can save us a lot of time when it comes to recovering databases in the likely event of unwitting incidents. On the top of that, in my experience it was shameful to see many environments without a backup strategy in place, even more, nobody was in charge of them.  In that context, it is clear that those businesses were surely at high risk of losing a lot of data and jaw-dropping amounts of money. Sometimes it is believed that having backups of the whole virtual machine is good enough, nevertheless, this sort of backup has a different purpose from a database backup. Thus, at no time can we replace SQL Server database backups with virtual machine backups which are time-consuming, inadequate, far-fetched for databases. In this sense, having implemented a suitable database backup strategy (Full + Diff + Log Backups) and carefully monitoring them are fundamental tasks to serve the needs of ensuring the recovery database process.
Broadly, it is of paramount importance to have a script at hand to find out whether or not specific sorts of backups were taken properly as well as how long they last, the size of the backup file, who took the backup, or if the backup was taken using CHECK_SUM option, etc. Today I am sharing that script which returns important information of backups for all databases in a SQL Server instance. In the following script, it filters out info of Full Backups (type='D'). You can use 'L' for Log Backup and 'I' for Differential Backup. So, try it out and make the most out of the info.

SELECT isnull(d.name,'') DatabaseName,
CASE is_read_only WHEN 1 THEN 'YES' ELSE 'NO' END as IsReadOnly, 
cast(sum(size)/128.0/1024.0 as decimal(8,2) ) as DBSize_InGB ,  
isnull( last_backup.recovery_model,'')RecoveryModel,isnull(last_backup.name,'') as BackupName ,
isnull(cast(last_backup.backup_start_date as varchar(24)),'(No Taken)') as BackupStartDate,  
isnull(case when [backup_size]>1024 then  cast( cast([backup_size]/1024.0 as decimal(8,2)) as varchar(12)) 
     + 'GB' else cast([backup_size] as varchar(12)) + 'MB' end,0) as BackupSize,
isnull(case when compressed_backup_size>1024 then  cast( cast(compressed_backup_size/1024.0 as decimal(8,2)) as varchar(12)) +
     'GB' else cast(compressed_backup_size as varchar(12)) + 'MB' end,0) as CompressedBackupSize ,
 isnull([duration],'') as Duration, isnull(is_copy_only,'') as IsCopyOnly, isnull(is_damaged,'') as IsDamaged,  
 isnull(has_backup_checksums,'') as HasBackupCheckSUM, isnull([user_name],'')as UserName
FROM master.sys.sysaltfiles  f
    inner join sys.databases d on f.dbid=d.database_id
    inner join (select database_name,backup_start_date, name, is_damaged,is_password_protected,
                has_incomplete_metadata,is_copy_only, cast(backup_size/1024.0/1024.0 as decimal(8,2))  as [backup_size], 
                cast(compressed_backup_size/1024.0/1024.0 as decimal(8,2))  as compressed_backup_size,
                isnull(cast(  CAST((DATEDIFF(second, bs.backup_start_date, bs.backup_finish_date))/3600 AS varchar) + ' hours ' 
                     + CAST(((DATEDIFF(second, bs.backup_start_date, bs.backup_finish_date))%3600 )/60 AS varchar)+ ' min'    as varchar(40) 
                ), '(No Available)') as [duration],bs.backup_finish_date, has_backup_checksums , [user_name], recovery_model
              FROM msdb.dbo.backupset bs
              WHERE bs.backup_set_id IN (SELECT MAX(backup_set_id) FROM msdb.dbo.backupset
                                                      where    type = 'D'
                                                     GROUP BY database_name) 
                AND bs.database_name IN (SELECT name FROM master.dbo.sysdatabases  )
                                ) as last_backup   on d.name = last_backup.database_name
                             where fileid<>2    
                             group by dbid,d.name , d.is_read_only,d.recovery_model_desc, last_backup.database_name, 
last_backup.backup_start_date,last_backup.[backup_size] ,last_backup.compressed_backup_size,last_backup.name, last_backup.duration,
 last_backup.backup_finish_date,is_copy_only,is_damaged,has_backup_checksums , [user_name], last_backup.recovery_model
ORDER BY DATEDIFF(minute,  last_backup.backup_start_date,  last_backup.backup_finish_date) desc

That is all for now, let me know any remarks you may have.

Getting the full name of SQL Jobs including the steps in execution

While monitoring a database server, we may need to know some details about the sessions, connections and requests that migh be causing performance or blocking issues so that we can take actions to fix them. In doing so, one very important piece of information is the program name that is connected to the database engine. Broadly, it is posible to see the program name in detail by using system stored procedures or DMVs such as 'sp_who2' and 'sys.dm_exec_sessions'. Nevertheless, not every name of the programs may be easy to interpret, especially when it comes to SQL Jobs. For instance, if you detected that a SQL Job is the root of the problem and then needed to know which SQL Job it is, the column program_name of 'sp_who2' or 'sys.dm_exec_sessions' woud only give us the SQL Job ID based on the following format:

SQLAgent - TSQL JobStep (Job 0x2613DA812CD2D248A9BA377DE6DEF355 : Step 1)

Obviously, we cannot do much with that info because there is no SQL Job name, and even worse, no SQL Job step name. However,  we can figure out the name of the SQL Job in msdb.dbo.sysjobs by using the ID.

SELECT * FROM msdb.dbo.sysjobs WHERE job_id=0x2613DA812CD2D248A9BA377DE6DEF355

Despite the fact that it may be relativily easy to get the name of the SQL Job, it is not enough because it is of paramount importance to know the name of the step in execution, and keep in mind that doing this manually this every time when needed is going to be an uphill battle as it is arduous and not optimal, especially if there are many SQL Jobs running and causing struggles. Thinking of this situation, I created a script to automate the task of figuring out details related to SQL Jobs such as the name and also the step name that is running. To be more precise, this logic is inside a function called "ufn_GetJobStepNameDesc" that takes the value of the "program_name" column and returns the name of the SQL Job and the step in execution. Let's take a look at the following code whereby we also filter out the sessions used by SQL Jobs.

SELECT session_id, login_time, login_name, [status], writes,

       logical_reads, [language], DB_NAME(database_id) DatabaseName,

          dbo.ufn_GetJobStepNameDesc([program_name]) AS SQLJobDescription

FROM sys.dm_exec_sessions where [program_name] like 'SQLAgent - TSQL%'

As you can see, I have highlighted the use of the function, and also added other important columns to look at as part of monitoring. So, using dbo.ufn_GetJobStepNameDesc([program_name]) the final outcome would be like this: SQLAgent - TSQL JobStep "<Name of the job step>" (Job: <Job name>).  For instance: SQLAgent - TSQL JobStep "Updating_Accounts" (Job: SAP_Financial_Process)

Here I share with you my script so that you can check it thoroughly and then make the most out if it.

USE [master]

GO

CREATE FUNCTION  [dbo].[ufn_GetJobStepNameDesc] (@step_name_desc VARCHAR(MAX))

RETURNS VARCHAR(max)

AS

BEGIN

       DECLARE @full_step_name_desc VARCHAR(MAX)

       DECLARE @jobstep_id_start INT

       DECLARE @jobstep_id_len INT

       DECLARE @jobstep_id INT

       SELECT @jobstep_id_start=CHARINDEX(': Step', @step_name_desc)+7, @jobstep_id_len=CHARINDEX(')', @step_name_desc)-@jobstep_id_start

       set @jobstep_id= CAST(SUBSTRING(@step_name_desc, @jobstep_id_start,@jobstep_id_len) AS INT)

       DECLARE @job_id_start INT

       DECLARE @job_id_len INT

       DECLARE @hexa_job_id VARBINARY(MAX)

       SELECT @job_id_start=CHARINDEX('(Job 0', @step_name_desc)+5,  @job_id_len=CHARINDEX(':', @step_name_desc)-@job_id_start

       SET @hexa_job_id=CONVERT( VARBINARY, RTRIM(LTRIM(SUBSTRING(@step_name_desc, @job_id_start,@job_id_len))),1)

      

       SELECT @full_step_name_desc='SQLAgent - TSQL JobStep "' + step_name+'" (Job: ' + j.[name] +')'

       FROM msdb.dbo.sysjobsteps js

            INNER JOIN msdb.dbo.sysjobs j ON j.job_id=js.job_id

       WHERE step_id=@jobstep_id and j.job_id=CAST(@hexa_job_id  AS UNIQUEIDENTIFIER)

       RETURN ( @full_step_name_desc)

END

That is all for now, I hope you find this post helpful. Let me know any remarks you may have. Stay tuned.

Error: could not obtain information about Windows NT group/user

Without any doubt, at times there is a need to use extended stored procedures in SQL Server, for instance, the following error may be raised while using 'xp_logininfo' to get information about domain account 'MyDomainMyAccount' (the account you are logged within SQL Server). The error may also appear when a SQL job, whose owner is a windows account, tries to authenticate against the Active Directory(AD) and this validation fails because of internal security reasons between SQL Server and the AD.

Error: 15404, State: 19. Could not obtain information about Windows NT group/user ‘MyDomainMyAccount’, error code 0x5.

In order to solve this error your Network Administrator has to enable ‘Allowed to authenticate’ security setting on the domain controllers computer object for the account 'MyDomainMyAccount' in the domain 'MyDomain' by following these steps:

1. logon to the Domain Controller of domain 'MyDomain'
2. open Active Directory Users and Computers (dsa.msc)
3. enable the ‘Advanced Features’ under the menu ‘View’
4. navigate to the domain controllers computer object and open the property window
5. click on the security tab
6. add the SQL Service account 'MyDomainMyAccount' and enable the setting ‘Allowed to authenticate’
7. click OK to close the window
8. repeat steps 4-7 on each Domain Controller computer object

Having done that, 'xp_logininfo' will run successfully bringing the information from the Active Directory. That is all for now, let me know any remarks you may have. Thanks for reading. Stay tuned.

sys.dm_exec_requests: total_elapsed_time column might return inconsistent data

Developing useful scripts for administration purposes, I have found a bug with respect to data recollected by 'sys.dm_exec_requests' dynamic management view on SQL Server 2008 R2 SP2 while I was analysing the total elapsed time for a particular SQL query. Let me expand on what I am saying. I did detect an error in the 17th second of the execution with 'session_id' equal to 63 (see it in the picture). Following the sequence of each result in the execution of queries, I need to draw your attention to the second query and its second column where the total elapsed time according to 'sys.dm_exec_requests' should be 17 and not 938 seconds since the previous one was 16. Now, checking the value of the third column (calculated by subtracting the 'start_time' value from GETDATE function), you will verify that this time is accurate whereas the second one is false. The value for the second and third columns should be the same but they are different.



To sum up, for this particular and real case, the column 'total_elapsed_time' returns inconsistent information about elapsed execution time of a process when it exceeds 16 seconds. Despite of the fact that I have not seen the same issue in other versions like SQL Server 2012/2014/2016/2017, it is better not to trust in DMVs so much. Therefore, I suggest working with caution. That is all for now, let me know any remark you may have. Stay tuned.

How to know which non-clustered indexes are not being used any longer

It is said that indexes are extremely useful to boost the performance of databases, especially indexes on huge tables. I am in agreement with that and I also support the idea of having the right indexes to achieve the best performance if they are created and used properly. Consequently, we have to vigilant of it, indexes may have been created to solve a particular problem in a moment, however, it does not mean that they are going to be useful forever but only for some days or months while data does not change too much. So, I should say as well that indexes are not the be-all and end-all for every business case, and we must always monitor the index usage and should consider the choose of dropping them if we verify they are not being using any longer. Keep in mind, not only could indexes be big and occupy a lot of space, but also impact on write operations negatively. Therefore, we should avoid wasting space, and having done that we can also optimise preventive indexes maintenance time.

This post will show a code to know exactly which non-clustered indexes are being used since the last restart of SQL Server engine. This code also filters out the indexes which are not related to primary keys. As you have seen in the code, we figure out the indexes by checking the value of columns user_seeks, user_scans, and user_lookups, if they are equal to zero then is says to us they were not used until this moment. Please be cautious, before using this code to get the indexes to be deleted, you should make sure that the database engine is not been restarted recently, otherwise, you will delete the wrong indexes and will impact on the performance tremendously. I strongly suggest using this code only if the latest restart of SQL Server has been done three months ago, more and less.

SELECT  i.type_desc,last_user_seek, last_user_scan, last_user_lookup,
        OBJECT_NAME(s.[object_id]) AS [Table Name] ,
        i.name AS [Index Name] ,
        i.index_id ,
        user_updates AS [Total Writes] ,
        user_seeks + user_scans + user_lookups AS [Total Reads] ,
        user_updates - ( user_seeks + user_scans + user_lookups ) AS [Difference]
, 'DROP INDEX ['+ schema_name(o.[schema_id]) +'].['+ OBJECT_NAME(s.[object_id]) +'].[' + i.name  + '];' as Statement_Drop_Index
,i.is_unique, i.is_unique_constraint, i.is_primary_key
FROM    sys.dm_db_index_usage_stats AS s WITH ( NOLOCK )
INNER JOIN sys.indexes AS i WITH ( NOLOCK )
INNER JOIN sys.objects o on o.object_id = i.object_id
    ON s.[object_id] = i.[object_id]  AND i.index_id = s.index_id
WHERE OBJECTPROPERTY(s.[object_id], 'IsUserTable') = 1
      AND s.database_id = DB_ID()     
      AND i.index_id > 1 and i.is_primary_key=0 and i.is_unique=0 and i.is_unique_constraint=0
      AND isnull(user_seeks, 0) + isnull(user_scans, 0) + isnull(user_lookups,0) =0 
ORDER BY  OBJECT_NAME(s.[object_id]), [Difference] DESC, [Total Writes] DESC,[Total Reads] ASC ;

When you execute it, you will also get a column containing the T-SQL code to delete the indexes which have not been used since the latest restart of SQL Server, and then you can execute it to delete them. To sum up, do not get me wrong, I am not against using indexes, on the contrary, I am in favour of using them properly, and if there were indexes that are not being using since a long time ago then they should be deleted. That's all for now. Let me know any remarks you may have. Thanks for reading.