1. Microsoft SQL Server Upgrade and Downgrade scenarios
Anastasia Staniloiu
Alexandru Dinica
Microsoft SQL Server Support Engineers

2. Agenda Why SQL Server upgrade?
Microsoft SQL Server Version Upgrade scenario
Why SQL Server downgrade?
Microsoft SQL Server Version Downgrade scenario
Announcements
Real-life situations

3. 1. Why SQL Server upgrade? more features
reduced total cost of ownership
more stability
more scalability

5. 2. Microsoft SQL Server Version Upgrade scenario

6. Upgrade scenario

7. Other tools Microsoft Assessment and Planning Toolkit a.k.a. MAP
-> Inventory the existing system
-> Check for breaking changes and mandatory code adaptations before being able to migrate

8. Database Migration Assistant a.k.a DMA
->Assess on-premises SQL Server instance(s) migrating to Azure SQL database(s). ->Discover issues that can affect an upgrade to an on-premises SQL Server. ->Discover new features in the target SQL Server platform that the database can benefit from after an upgrade.

9. SQL Server Migration Assistant a.k.a. SSMA
->SQL Server Migration assistant has the same purpose as Database Migration Assistant except that it’s designed for migrating data from a particular RDBMS that is not SQL Server. ->There are multiple versions of SSMA, one for Oracle, one for MySQL, one for DB2…

10. Performance

11. High Availability

12. Query store
Pinpoint and fix queries with plan choice regressions 1
Identify and tune top resource consuming queries 2
Keep performance stability during the upgrade to newer SQL Server 3
Identify and improve ad hoc workloads 4

13. Postupgrade

14. 4. Microsoft SQL Server Version Downgrade scenario

15. BEFORE DOWNGRADE
Backup the databases (system and user databases)  
Delete the local security groups. Before you uninstall SQL Server, delete the local security groups for SQL Server components.

16. Please make sure that you've not used any of the enterprise edition feature. In order to check it run the following query on each database:  
Script all the logins. How to transfer logins and passwords between instances of SQL Server: film)

17. Stop the SQL Server service. 
Copy the master, model, and msdb database files (both .mdf and .ldf), from the current location to a new folder that you mark as readonly.  
Uninstall SQL Server from the system. 

18. Uninstall an Instance of SQL Server 
1.     To begin the uninstall process, go to Control Panel and then Programs and Features. 
2.     Right click Microsoft SQL Server #### and select Uninstall. Then click Remove. This starts the SQL Server Installation Wizard. 
                                                                 i.     Setup Support Rules runs to verify your computer configuration. To continue, click Next. 
3.     On the Select Instance page, use the drop-down box to specify an instance of SQL Server to remove, or specify the option to remove only the SQL Server shared features and management tools. To continue, click Next. 
4.     On the Select Features page, specify the features to remove from the specified instance of SQL Server. 
                                                                 i.     Removal rules runs to verify that the operation can complete successfully. 
5.     On the Ready to Remove page, review the list of components and features that will be uninstalled. Click Remove to begin uninstalling 

19. 6.     Immediately after you uninstall the last SQL Server instance, the other programs associated with SQL Server will still be visible in the list of programs in Programs and Features. However, if you close Programs and Features, the next time you open Programs and Features, it will refresh the list of programs, to show only the ones that are actually still installed. 
Microsoft resource :

20. Reboot the server 
Install SQL Server Standard Edition. 
Microsoft resource:
Shut down SQL Server. 
Copy the master, model, and msdb database files (both .mdf and .ldf) from the folder you saved them in to the correct location for the new install and remove the readonly flag from the files, and change the file ACL’s so that the SQL Service account has Full Control over the files. 
Start SQL Server. It will start up and be exactly where you were before you made any changes, with all of your user databases online and you should be ready to let applications connect and resume operations. In case there is something going wrong, we have the backups of the databases and logins. 

21. 4.1 After the downgrade or upgrade What to do after a migration ?

22. Download the DEA tool, and then install it.
Run a trace capture
a. On the left navigation tree, select the camera icon the go to All Captures
b. To start a new capture, select New Capture.

23. c. To configure the capture, specify the trace name, duration, SQL Server instance name, database name, and the share location for storing the trace file on the computer running SQL Server.
d. Select Start to begin trace capture.

24. 3. Run a trace replay
a. On the left navigation tree, select the play icon the go to All Replays.
b. To start a new replay, select New Replay.
c. To configure the replay, specify the replay name, controller machine name, path to source trace file on controller, SQL Server instance name, and the path for storing the target trace file on the computer running SQL Server.
d. Select Start to begin replay of your capture.

25. 4. Create a new Analysis Report
a. On the left navigation tree, select the checklist icon to go to Analysis Reports.
b. Connect to the SQL Server on which you will store your report databases.
You will see the list of all reports in the server.
c. Select New Report.
d. To configure the report, specify the report name, and specify paths to the traces for the source and target SQL Server instances.

27. 5. Review an analysis report
a. On the first page of the report, the version and build information for the target servers on which the experiment was run displays.
Threshold allows you to adjust the sensitivity or tolerance of your A/B Test analysis.
Note: By default, threshold is set to 5%; any performance improvement that is >= 5% is categorized as ‘Improved’. The drop-down selector allows you to evaluate the report using different performance thresholds.
b. Select the individual slices of the pie chart to view drill-down metrics on performance.

28. 6. Real-life situations