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Category: Linked server

SQL2016 Stretch database. Yes, it’s another linked server

Your manager always wants to keep all the data…now with bigdata being a thing and algoritmes are used more efficient (IOT), people want to hoard data even more, but it needs to be online to be valuable. If you have to restore the data first, your data is not very valuable. But all this extra data also slows down your database performance…and gives the dba’ers extra challenges….but not anymore.! Well, at least when your boss got a big wallet and don’t mind spending it on a SQL buget.

In SQL2016 Microsoft introduced the stretch database. which give you live access to ‘archived’ data and makes it feel like it’s on premise. And  it’s a secretly just a linked server! A linked server between mssql and Azure.LS+azure

How does this work, and is it safe?

Yes! since it works on secure linked server technology and it stores an encryption key on the on-premises sqlserver, it’s suitable for all your cold data, not hot, because it does slow down the query speed, but it will not clogg your network and your data will be available at all times, even when the data is being stretched over to Azure the data still is fully query-able.

First ask yourself, Do you really need to keep this data? If yes, How do you create a stretchdatabase? Well, this is easy!

Hesitations? use this link for info on the MS Stretch database advisor.

I use a simple test database, the adventureworks2016 ctp3.

Before we can start, check if the data archive function is enabled, if not (0) enable it.

####Check status of Remote data archive####
SELECT @@VERSION AS 'SQL Server Version'; 
EXEC sp_configure 'remote data archive'; 
GO 
####Activate Remote data archive####
EXEC sp_configure 'remote data archive' , '1'; 
GO 
RECONFIGURE; 
GO

Next we can create a master key to encrypt all your data locally, this way, the data can’t be read in Azure.
Note: You can also create a masterkey from the stretchdb wizard, it’s up to you. I’ll show both options.

USE AdventureWorks2016CTP3; 
GO 

CREATE MASTER KEY ENCRYPTION BY PASSWORD='stretchdb2016'; 
GO

Next I will create a simple table  and populate it with some data, to keep the demo quick and simple :

CREATE TABLE dbo.Stretchtable
(
FirstName VARCHAR (50),
LastName VARCHAR (50)
);
GO


Use [AdventureWorks2016CTP3]
GO
INSERT INTO dbo.Stretchtable (FirstName, lastName)
VALUES ('Reed', 'Richards'), ('Benjamin', 'Grimm'), ('Sue', 'Storm'), 
 ('Johnny', 'Storm'), ('Victor', 'Von Doom'), ('Willie','Lumpkin');
 GO

Keep your Azure account ready! I use the SQL logical server resource, you need to create a resource before you can stretch the database.

Azure resource

 

Select the table you will be stretching to Azure. Now enable the table for stretching and the wizard will open up.

Enable stretch database

It’s a Hybride archive – You can stretch the whole table or filter out the (c)old data from a massive table.
4_EnableStretchTable

 

Next thing you create a master key, if you didn’t make it before, if you made it already, It will ask you to fill in the master password.Masterkey_StretchTable
10_LoginStretchTable

Fill in the IP range for a firewall rule.IP_Azure

12_EnableStretchTable

Hey Ho, let’s go, that was easy!

Now the table will start to stretch, if you want to see if it stretched yet, try a select query and check the executionplan.
14_EnableStretchTable

Want your data back? No problem, You can bring back the data to your on-premise server, if you don’t want to use Azure. Because, when you delete your azure account, the data will be gone too!

bringbackmydatabringbackmydata2bringbackmydata3

 

Note: Data storage can be expensive on Azure, but this function gives us a positive view on the ever growing databases and it’s possibilities.


Linked server #Back to Basics

Really back to basic, but here is another example how to move data from one server to the other in a scheduled job.

First make sure, when you use an sql account to connect both servers, the account exist on both ends of the line.

Now we create a linked server, after all my former tutorials, I don’t have to go into detail, either script it or use SSMS gui, un this case I’m using it for a MSSQL to MSSQL this is easy peasy.

LS_make

Create a database and table if it doesn’t exsist on the server you want to insert the data in.

If all is setup, write a simple INSERT INTO script:

INSERT INTO [FunFactory_II].[dbo].[Accounts_NAWT]
(AccountNumber]
,[Name]
,[Street]
,[PostalCode])
SELECT
[AccountNumber]
,[Name]
,[Street]
,[PostalCode]
FROM [FunFactory_I].[dbo].[BSN].[Accounts]

And the last step is to create a job, to start the import automatically and schedule it to run on a given time.

This is my really #back to basic linked server tutorial, but you can add and tweak functions into the script and built fully automated solutions for your data.

For example a scheduled sql job to insert data from the linked server.
insertIntoFF


Linked server to Microsoft Azure #Error 405150

When Azure was launched, we missed one important feature, the linked server, It seemed impossible to do cross database queries from your local database to the Azure database, but Microsoft listened and made it possible to do database queries that spans multiple databases across platforms.

There is plenty of hits when googled on the errors, but none of these are complete! I will write down the  process of linking your server to Azure.

when I first created a linked server to Azure, I got this error  “reference to database and/or server name is not supported in this version error: 405150”, When trying to add a linked server from SSMS, you are not given option to set a default database. So I used Tsql instead, because without a specific catalog, your linked server will not work.LS_Azure

Azure doesn’t allow you to alter the master db, so you have to connect directly on the database you are going to use.

What people never tell LS newbies and make you google this error “Msg 2812, Level 16, State 62, Line 1 Could not find stored procedure ‘sp_addlinkedserver’ ” and read tons of blogs and tutorials all providing different queries, but still no work, follow these steps”.

The Tutorial, the Solution:

Open up ODBC, or simply run odbcad32.exe. and start by making a new system DNS with the Native client.

ls_SYSDNS

In the next step, you provide your datasource name and the complete server name as you can find on the Azure server.

LS_makedns

Also provide the database you want to connect to, don’t skip this one!

LS_Choosedb

 

Test the connection, see it succeed! if not, go through the above printscreens you probably missed a step.

LS_Testsuccesf

Now we can create the linked server on your database, by creating a query on your SSMS and can run your linked server query, it should look similar to this:

EXEC master.dbo.sp_addlinkedserver @server = N’Azure_server’, @srvproduct=N”, @provider=N’sqlncli’, @datasrc=N’t20ko02v18.database.windows.net’, @catalog=N’Teletraan IV’ EXEC master.dbo.sp_addlinkedsrvlogin @rmtsrvname=N’Azure_server’, @useself=N’False’,@locallogin=NULL,@rmtuser=N’skyscream’,@rmtpassword=’password’

To test if the LS is added, you could run exec sp_helpserveror just test the connection.LS_SPhelpserver

These are all the steps to a Linked Azure server. Congratulations, you are now connected to the Azure mothership of data.

Data manipulation

Next step is to insert data from the Azure linked server into our local database. Btw, this query works both ways, you could also insert data into the Azure database.

Create an INSERT statement

BEGIN TRAN INSERT INTO [Azure_demo].[dbo].[Demo] (Initials,Prefix,LastName,Gender,Street,HouseNumber ,Zipcode,City,PhoneNumber,MobileNumber,EmailAddress) SELECT Initials,Prefix,LastName,Gender,Street,HouseNumber ,Zipcode,City,PhoneNumber,MobileNumber,EmailAddress FROM [Azure_server].[Teletraan IV].[dbo].[AzureData] WHERE InsertDate BETWEEN ‘2008-08-22 00:00:00.000’ AND ‘2009-02-06 00:00:00.000’ ROLLBACK TRAN –COMMIT TRAN

Ls_Qresult

Now all rows have been added through our linked server into our local database. LS_Check
If this blog saved your ass or just made your day, please let me know 🙂


Linked server setup – Back to basics (error 7399)

I recently received this question:

Why am I getting an error ‘Invalid authorization specification’. I used my SA account, but i keep getting the error that the credentials specified are incorrect.

There is a very simple answer to this question, which I will share with you.

The error you get when the credentials are invalid:LSSLinked server is a connection between two servers in your network. If you want to connect the servers, the specified credentials need to be known on both servers, So, unless you use the same password for sa acounts on all your network server, which is never recommended in the first place! I advise you to create a specific Linked server sql account, for example I created a LS_2014 account on both servers and specified on which databases the Linked server is allowed to read and select data, as you can see in the example below.

ls_account

ls_acc

This keeps your databases secure and easier to manage.

You could also set it to use your current logged in account, but you need enough permissions on all servers and depending on who is using the SQL server, the linked server might not be available.

If you use the account specifically created for the Linked server and test the linked server account, the connection will be successful and you will see the table you granted read permissions on is available in the linked server dropdown.


Creating a linked server ´MySQL to MSSQL´(query the MySQL database without openquery function)

In addition to my previous linked server tutorials, I decided it is time to add MySQL to the linked server series.
In order to have the bug tracking application, Mantis migrated from linux and have it run on a windows environment, I wanted to create a replication between SQL2008 and MySQL, but then I thought, why not try out a virtual linked server again first, to test Mantis isntallation on a Windows based installation, since the online promise of Mantis on a MSSQl environment is not very promising. So today we will create a linked server from MySQl to MSSQL on a windows 2008R 64 bit environment.

Create DNS for MySQL

In order to do so, We first need to install the correct drivers in order to create a ODBC DSN, Just download the drivers from Mysql developers site http://dev.mysql.com/downloads/connector/odbc/ and install them to your database server. DriversIf we see the listed drivers, it means we can create a new DSN, so open up the System DSN tab and ADD a new DSN, you must fill in the correct credentials, for example:ODBC_Connector

Data Source Name: Enter a describing name, so you can see what it does, you might have more linked servers or other connectors running on the same server.
Description: this isnt maditory, but if you want to be more specific, be my guest.
Server: in my case,it’s localhost, as this is a test server and MSSQL and MySQl are on the same server.
Insert username and password, when this is done. The database will display the possible databases you can connect to, in the dropdown.

Click OK and as you can see the System DSN has been added to ODBC.

Create new Linked Server

When this is done, it’s time to open up the MSSQl server and add a new linked server to the Server Objects.4_create_LInkedsname your linked server, I give it the same name as the SystemDSN. And choose the correct provider: Microsoft OLE DB Provider for ODBC Drivers. and datasource equels DSN name.
You need to fill in all the credentials for the provider string, for example:

DRIVER=(MySQL ODBC 5.2 ANSI Driver);SERVER=localhost;PORT=3306;DATABASE=mantisbt; USER=user;PASSWORD=password;OPTION=3;

Note: meaning of OPTION=3 in the MySQL connection string:
Option=1 FLAG_FIELD_LENGHT: Do not Optimize Column Width
Option=2 FLAG_FOUND_ROWS: Return matching rows
Option=3 option 1 and 2 together

Now click OK, this is always the most fun part to me! when it says connection tot the linked server succeeded!

In addition to this, you can enable provider options on the SQLOLEDB, In my case I select the Dynamic Parameter and Allow inprocess.

Now, lets run the test and see if it connects with the databases, as you can see, it connects all the databases available on the MySQL server.

Connection test

But, most important, we can query it directly. Wheeee!

Linked server without OpenQuery function (Tip!)

Maybe you have read other MySQL linked server tutorials before this one and found out that you could only query the mysql database using the openquery() function or maybe that IS  the reason it brought you to this site. Extra, as in extra work, is never fun! With the correct ODBC driver and the right provider options, you can query the MySQl database, just like any other MSSQL database on your MSSQL server. Just follow the tutorial above and don’t forget to  enable the correct provider options. Cheers!