189 C H A P T E R 9 | Introducing Azure SQL Data Warehouse
Settings blade. Click the Copy button to the right of one of the keys to store an access key on the
clipboard.
Next, use the AzCopy utility to upload your text file. To do this, open a command-prompt window and
go to the AzCopy installation directory like this:
cd /d "%ProgramFiles(x86)%\Microsoft SDKs\Azure\AzCopy"
Then, after replacing the placeholder tokens with the blob service endpoint and storage account key,
run the following AzCopy command:
.\AzCopy.exe /Source:C:\Temp\ /Dest:/datacontainer/dimsalesterritory/
/DestKey: /Pattern:DimSalesTerritory.txt
Now open SSDT, connect to your SQL Data Warehouse in SQL Server Object Explorer, and then right-
click the database and click New Query. Next, you must configure authentication as shown in Example
9-6 to create a master key and add a database-scoped credential to your SQL Data Warehouse that
PolyBase uses to access the data in blob storage. In the CREATE DATABASE SCOPED CREDENTIAL
statement, you can use any string value for IDENTITY because it is not used during authentication, but
replace the placeholder token for SECRET with the same storage account key that you used to copy
data into blob storage.
Example 9-6: Configuring authentication for access to blob storage
-- Create a master key if one does not already exist
CREATE MASTER KEY;
-- Create a database-scoped credential
CREATE DATABASE SCOPED CREDENTIAL AzureDWDataStorageCredential
WITH
IDENTITY = 'user',
SECRET = '';
Then you need to create the following external objects in SQL Data Warehouse, as shown in Example
9-7:
External data source Identifies where to find your blob storage. The LOCATION argument
requires the name of the blob container and storage account into which you uploaded your data.
The CREDENTIAL argument uses the database-scoped credential that you added to the SQL Data
Warehouse earlier. For more information about creating an external data source and about using
PolyBase to access a Hadoop source, see https://msdn.microsoft.com/en-
us/library/dn935022.aspx.
External file format Describes the structure of your data. The FORMAT_TYPE argument takes
one of the following values: DELIMITEDTEXT, RCFILE, ORC, or PARQUET. For more information
about creating an external file format and the various ways to use define formats, see
https://msdn.microsoft.com/en-us/library/dn935026.aspx.
External table Provides the table definition and location of data. Here you must include the
column names and data types, provide the directory relative to the blob storage container that
holds your data, reference the external data source, and specify the file format. For more
information about creating an external table, see https://msdn.microsoft.com/en-
us/library/dn935021.aspx.
Example 9-7: Creating external objects
