Azure SQL update statistics (Manual)

I recently run into a case where I needed to update statistics of an Azure SQL Database because of poor performance and deadlocks. Preventing disruptions is key, so it is important to do something about it. With a simple script we can update the statistics easaly.

Why should I update statistics?

SQL Server statistics are essential for the query optimizer to prepare an optimized and cost-effective execution plan. These statistics provide distribution of column values to the query optimizer, and it helps SQL Server to estimate the number of rows. The query optimizer should be updated regularly. Improper statistics might mislead query optimizer to choose costly operators such as index scan over index seek and it might cause high CPU, memory and IO issues in SQL Server. We might also face blocking, deadlocks that eventually causes trouble to the underlying queries, resources.

The script

Just execute the following query on your database and you should be good to go! Keep in mind, depending on your database this might take a while. During this script your database will get slow, but will remain online.

SET NOCOUNT ON
 GO

 DECLARE updatestats CURSOR FOR
 SELECT table_schema, table_name  
 FROM information_schema.tables
        where TABLE_TYPE = 'BASE TABLE'
 OPEN updatestats

 DECLARE @tableSchema NVARCHAR(128)
 DECLARE @tableName NVARCHAR(128)
 DECLARE @Statement NVARCHAR(300)

 FETCH NEXT FROM updatestats INTO @tableSchema, @tableName

 WHILE (@@FETCH_STATUS = 0)
 BEGIN
    SET @Statement = 'UPDATE STATISTICS '  + '[' + @tableSchema + ']' + '.' + '[' + @tableName + ']' + '  WITH FULLSCAN'
    EXEC sp_executesql @Statement 
    FETCH NEXT FROM updatestats INTO @tableSchema, @tableName
 END

 CLOSE updatestats
 DEALLOCATE updatestats
 GO
 SET NOCOUNT OFF
 GO

Azure Private Link now available in Preview!

With an increased security and privacy in mind Microsoft has been working on private links to Azure resources. Azure Private Link is a secure way to consume Azure Services like Azure SQL and Azure Storage using a private connection in your own VNet. This will replace the need for IaaS hosted virtual machines with SQL Server or the file server role installed.

Afbeeldingsresultaat voor azure private link

Azure Private Link brings Azure services inside the customer’s private VNet. The service resources can be accessed using the private IP address just like any other resource in the VNet. It is basically an NIC inside one of your VNET’s. This will allow all traffic to flow over the internal network, and will not go over the internet. There is no need to put gateways or any other network devices in place to make this happen.

Continue reading “Azure Private Link now available in Preview!”

Azure SQL configure Azure AD user authentication (Manual)

When moving your applications to the cloud, it makes sense to start using Azure Services to get the best service, highest availability (SLA) and worry free maintenance provided by Azure. The next step is to use Azure AD identities with Azure SQL Database.

Schematic overview of Azure SQL with AAD integration, and optionally synced from on-premise AD.

Within a few steps you will have Azure AD user authentication setup.

Continue reading “Azure SQL configure Azure AD user authentication (Manual)”

Azure SQL, create users and assign permissions (Manual)

This simple manual has been created to create an user in Azure SQL and assign appropriate permissions. First connect to your SQL server. Either use and AAD admin account or the SQL Admin account.

Once connected, open a New Query window and run the following command on the Master database to create the user on the server in the Master database:

 CREATE LOGIN '<Username>' WITH password='<strong-password>';

Now open again a New Query window, and select the database where you want to provision permissions to the just created user. Make sure to match the Username from the command above.

CREATE USER "<Username>";

The last step is to assign the desired role to the user. Change the value of the role, and match again the Username.

EXEC sp_addrolemember 'db_datawriter', '<Username';

This should do the trick. Let me know if you have any problems or need help.