Database Reference
In-Depth Information
Database server is 150, including the system database master. Each row in a Windows Azure
SQL Database table can contain 1024 columns, which can be up to 8 MB in size. For security
reasons, some of the commonly known user names such as admin, administrator, guest, root,
and sa cannot be used in Windows Azure SQL Database. To eiciently use Windows Azure
SQL Database resources, the connection to Windows Azure SQL Database will be automatically
closed under circumstances such as idle for 30 min or longer, failover due to server failures, or
excessive resource usage.
Most of the remote access tools and database management tools available to Microsoft SQL
Server are also available to Windows Azure SQL Database. When a company needs a database
that is accessible anywhere and anytime, Windows Azure can serve that purpose nicely. Also,
Windows Azure SQL Database allows databases to be scaled up or scale down along with time.
herefore, it can provide a highly scalable data source to support web-based applications.
2.4.2.2 Windows Azure Storage
In addition to Windows Azure SQL Database, Windows Azure provides Windows Azure Storage
service for handling nonrelational data. Also, Windows Azure can use storage space on local
computers.
1.
Local Storage
: A running Windows Azure application project uses local storage as tempo-
rary storage. Local computer data generated by an application instance are temporally stored
on the local hard drive. he data are only accessible by the application on the local machine
and is not transferable when the application is moved to a diferent local computer. he data
can be lost when rebooting the local computer. he default local storage size is 1 MB. An
application instance can have multiple local data stores.
2.
Windows Azure Storage
: Unlike local storage, Windows Azure Storage Services are acces-
sible anywhere and anytime. Windows Azure Storage Services include three components,
Windows Azure Table Service for eiciently storing a large amount of data, Windows Azure
Queue Service for the storage of messages, and Windows Azure Blob Service for the storage
of large binary objects such as video and audio iles. he maximum of 100 TB storage space is
available for each Windows Azure Table Service storage or Windows Queue Service storage.
he maximum of 1 TB storage space is available for each Windows Azure Blob Service storage.
a.
Windows Azure Blob Storage
: Multimedia content such as video, audio, and image is
usually saved as binary data. Windows Azure Blobs are used to store the binary content.
he snapshots of the Blob can be used for backup. he Blob can also be cached at the
nearby data center for fast data access.
b.
Queue Storage
: Similar to Microsoft Message Queuing (MSMQ), Windows Azure
Queue Storage is used to process messages between applications. he messages are irst
placed in a queue and then processed in a irst-in-irst-out (FIFO) manner. In case an
application fails to process a message, the message will be kept in the queue and wait to
be processed by another application. While one application is reading the message, the
message is marked as invisible until the message is deleted or a speciied reading interval
is reached. By doing so, it prevents a message from being processed by multiple applica-
tions simultaneously. By default, the size of a message is limited to 8 kB.
c.
Table Storage
: Windows Azure ofers Table Storage for storing a large amount of struc-
tured data. he data in Table Storage are structured as rows and columns. According
to Windows Azure's terminology, rows are also called entities and columns are called
