Archive for the ‘Error Messages’ Category

Interesting error today:

When we query over linked server, we run into some restrictions. One such restrictions is this, where we could not query XML columns over LinkedServer connection.

For example, if the remote server table has a XML column in its structure, when we query the remote server for this table, we run this error:

-- Old query that throws this error
FROM LinkedServer01.DatabaseName.dbo.TableName
Error : Msg 9514, Level 16, State 1, Line 1 
Xml data type is not supported in distributed queries. 
Remote object has xml column(s)


Not sure why this limitation exists, but there is a workaround: OPENQUERY

In the past, we’ve covered some key benefits of OPENQUERY and how it allows us to circumvent some limitations of remote-table-value function calls. Today, we’ll see another benefit of OPENQUERY in circumventing the XML limitation of linked servers.

Rather than querying XML directly, we convert XML into NVARCHAR(MAX) and revert it back to XML once the data is on local server.

-- Modified query to circumvent the limitation
FROM OPENQUERY(LinkedServer01,
	FROM DatabaseName.dbo.TableName') AS RemoteQuery

The XML data is retrieved as NVARCHAR(MAX) to the local machine; And immediately converted to XML before displaying.


Hope this helps,

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Quick one today:

Every time we we build a new cluster in our lab environment, we start with running cluster validation report before starting Sql Server installation. Once in a while, we need to go back to refer older validation reports.

All cluster validation reports are saved, by default, at the location below on the active node where the validation was executed from:




Hope this helps,


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Interesting Error today:

While playing with XML DML, ran into this cryptic error.

Msg 2207, Level 16, State 1, Line 89
XQuery [dbo.Table.XMLColumn.modify()]: Only non-document nodes 
can be inserted. Found "xs:string ?".


While INSERTing a new XML element into an existing XML column, using the below code, this error pops up:


DECLARE @NewXMLElement VARCHAR(50) = 'Test'

UPDATE dbo.TableName
SET XMLColumn.modify('
		insert sql:variable("@NewXMLElement")
		into (/Parent/Child)[1]
WHERE XMLColumn.exist('(/Parent/Child/NewXMLElement/text())') = 0


Here, the goal is to INSERT a XML snippet into an existing XML column value. So, it is important that in the modify() function, the new XML element variable is defined as XML datatype

DECLARE @NewXMLElement XML = 'Test'

UPDATE dbo.TableName
SET XMLColumn.modify('
		insert sql:variable("@NewXMLElement")
		into (/Parent/Child)[1]
WHERE XMLColumn.exist('(/Parent/Child/NewXMLElement/text())') = 0


Hope this helps,


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Interesting one today:

In our lab environemnt, one of the SQL cluster environment ran into this error.



Error Message:

Clustered role 'Cluster Group' has exceeded its failover threshold.  
It has exhausted the configured number of failover attempts within 
the failover period of time allotted to it and will be left in a 
failed state.  
No additional attempts will be made to bring the role online or fail 
it over to another node in the cluster.  Please check the events 
associated with the failure.  After the issues causing the failure are 
resolved the role can be brought online manually or the cluster may 
attempt to bring it online again after the restart delay period.

The Cluster service failed to bring clustered role 'Cluster Group' 
completely online or offline. One or more resources may be in a 
failed state. This may impact the availability of the clustered role.


Errors like this are more common in Lab environments than in production environment. In any case, if you encounter the same error in production environment, then take extra caution before you follow these steps.

Possible Root Cause:

In lab sometimes, as part of some other effort, we inadvertently end up failing over the cluster several times within a short period of time. There is a setting in Cluster that measures the failover count.

  • If that count hits a particular threshold, it flags the Resource Group as ‘Failed’ state
  • And creates an entry in the the Cluster Events, that Cluster Resource Group failed after reaching the threshold (see the error message : Clustered role ‘Cluster Group’ has exceeded its failover threshold)

Resolution Steps:

According to this MSDN post, we could alter that failover count threshold to allow the resource group to come back up in a healthy state.


Step 1:

Go to Failover Cluster Manager >> Roles >> right click on the Resource Group and to go Properties:

  • Change the Maximum failures in a specified period to a larger number to account for the repeated failovers in recent hour.




Step 2:

Go to Failover Cluster Manager >> Roles >>

In the bottom portion of the window where we the individual resources are listed, right click on the Resource that is in failed state and go Properties:

  • Increase the Maximum restarts in the specified period setting to a larger number to account for recent restarts.




NOTE: This is not a standard solution for production environments.

Hope this helps,

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Quick one today

Once in a while, we need to process XML files (a.k.a. deadlock XML files) to retrieve some pertinent information to uncover the deadlock patterns.

In the past, we’ve seen some XML DML queries to parse XML files.

Here we’ll focus on filtering capability based on attribute values in elements:

Take an deadlock XML for example:


The goal is to search for the action element with attribute value as “collect_system_time“.

-- Parse & Filter XMl file data
	  ROW_NUMBER() OVER(ORDER BY DeadLockXML.value('(/event/@timestamp)[1]', 'DATETIME2'))											AS [RowN]
	, DeadLockXML.value('(/event/action[@name="collect_system_time"]/value)[1]', 'DATETIME') AS SystemTime
FROM  dbo.Deadlocks_07262018_Step2

The [] allow us to provide the value to filter the XMl elements:



Hope this helps,


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Quick one today:

Quite often, we all run into this scenario where we need to convert column data into row with either comma or some other delimiter.

Below, we’ll see a couple of ways; Each serving a different purpose:

Build data set first:

--  Convert row data into column (without using PIVOT)

-- Create tables
	, Name	VARCHAR(20)

	, ParentID	INT
	, Name		VARCHAR(25)

-- Create Parent records
INSERT INTO Parent (Name) VALUES ('Mary')
INSERT INTO Parent (Name) VALUES ('Patel')
INSERT INTO Parent (Name) VALUES ('Risvic')

-- Create child records
INSERT INTO Child (ParentID, Name) values (1, 'Jil')
INSERT INTO Child (ParentID, Name) values (1, 'Jim')
INSERT INTO Child (ParentID, Name) values (1, 'Kat')

INSERT INTO Child (ParentID, Name) values (2, 'Raja')
INSERT INTO Child (ParentID, Name) values (2, 'Kamat')


Data set looks like this:


Option 1 : Using Variable

This method gives us result in comma delimited fashion, but it only works for one parent at a time; And we cannot combine Parent name as a column next to Children column, as Sql Server does not allow combining data-retrieval with variable manipulation query.

It spits out an error like this:

Msg 141, Level 15, State 1, Line 35
A SELECT statement that assigns a value to a variable must not be 
combined with data-retrieval operations.
--	Option 1 : using @Variable
DECLARE @Children VARCHAR(8000)

SELECT @Children = COALESCE(@Children, '') + ', ' + Name
FROM dbo.Child
WHERE ParentID = 1

SELECT STUFF(@Children, 1, 2, '')


Option 2 : Using XML

XML PATH gives us more control over retrieval manipulation. It allows us to retrieve data in a tabular fashion, while keeping the children names into one column.


This below query has 3 parts:

  1. Main warp-around query (Parent)
  2. STUFF section
  3. XML PATH section
--	Using XML
SELECT    P.ID	AS [ParentID]
	, P.Name	AS [ParentName]
					SELECT ', ' + C.Name
					FROM dbo.Child AS C
					WHERE C.ParentID = P.ID
					FOR XML PATH('')
				, 1, 2, ''
		  ) AS [Children]
FROM dbo.Parent AS P

-- Clean up


We’ll see the details of each query in reverse order:


This is the most important part of this whole query. It allows us to retrieve all children of a given parent in a comma delimited fashion.

Without FOR XML PATH(”) statement, this is just a query that returns children as rows. When you add FOR XML, that data set is now converted into XML format (sort of).

PATH (”) makes sure that the the element trees notation is replaced with whatever is in between ” (empty). So we get a simple comma delimited child list.

Now we have an extra comma to remove. That’s where STUFF comes into play.

STUFF query section replaces comma with empty space.

Main wrap-around query is to bring this all together with ParentID & Parent Name to make it more usable.


Hope this helps,


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Quick one today:

Extended Events make it easy to capture deadlock details into an XEL file, that has deadlock data in XML format.

This XEL file could be imported into a Sql table using sys.fn_xe_file_target_read_file function; It is similar to ::fn_trace_gettable function to load Sql trace file into a table.

SELECT * INTO dbo.DeadlocksXML
FROM sys.fn_xe_file_target_read_file ('I:\Deadlocks\xml_deadlock_report_0_131771103583570000.xel', null, null, null)

MSDN also has an article on this function.

Hope this helps,


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