The windows Azure platform offers different mechanisms to store data permanently. In this article I would like to introduce the storage types of Windows Azure.

Storage Types:

If you want to store data in Windows Azure you can choose from four different data sources:

·         Queues

·         Blob Storage

·         SQL Azure

·         Table Storage

Windows Azure Queues:

The Queue service stores message that may be read by any client who has access to the storage account. A queue can contain an unlimited number of messages, each of which can be up to 64KB in size using version 2011 – 08 – 18 or newer. For previous versions, the maximum size of a message is 8KB. Messages are generally added to the end of the queue and retrieved from the front of the queue.

If you need to store messages larger than 64KB, you can store message data as a blob or in a table, and then store a reference to the data as a message in a queue.

The Queue service exposes the following resources via the REST API:

·         Account: The storage account is a uniquely identified entity within the storage system. The account is the parent namespace for the Queue service. All queues are associated with an account.

·         Queue: A queue stores messages that may be retrieved by a client application or service.

·         Messages: Messages are XML-compliant and may be up to 8 KB in size.

Windows Azure Blobs:

The Blob service stores text and binary data. The Blob service offers the following resources: the storage account, containers, and blobs. Within your storage account, containers provide a way to organize sets of blobs.

You can store text and binary data in either of two types of blobs:

·         Block blobs, which are optimized for streaming.

·         Page blobs, which are optimized for random read/write operations and which provide the ability to write to a range of bytes in a blob.

SQL Azure:

SQL Azure delivers cloud database services which enable you to focus on your application, instead of building, administering and maintaining databases. It is built on SQL Server technologies and is a component of Windows Azure platform.

The beauty of SQL Azure is that you as a developer can work with SQL Azure just like you work with your SQL Server. SQL Azure supports the majority of programming features that you are used to. You can access it using ADO.NET, Entity Framework or any other data access technology that you want.

Table Storage in Windows Azure:

In windows azure we can use Table service API to create tables for structured storage, and to insert, update, delete, and query data. The Table service API is a REST API for working with table and the data that they contain.

The Table service API is compliant with the REST API provided by ADO.NET Data Services, with some differences. The Table Service API restricts some functionality that is defined in the ADO.NET Data Services Framework. The API also provides some additional functionality that is not available through ADO.NET Data Services.

The table service offers structured storage in the forms of tables. Tables store data as collection of entities. Entities are similar to rows. An entity has a primary key and set of properties. A property is a name, typed-value pair, similar to a column.