Wednesday, March 2, 2011

SQL Azure - An Introdution

*Shared infrastructure at SQL database and below
->Request routing, security and isolation
*Scalable HA technology provides the glue
->Automatic replication and failover
*Provisioning, metering and billing infrastructure

*SQL Azure Connectivity and working Process Model

SQL Azure Development

SQL Azure's relational database service supports the T-SQL (Transact-SQL) over TDS (Tabular Data Stream)
protocol. The relational data model in the cloud can therefore be used together with current T-SQL developments.
The new distributed functionality of the SQL Azure Database in the cloud should provide development cost-savings,
as existing applications, tools and expertise can be incorporated. The ability to use the traditional RDBMS data
model in the cloud implies that developers should be able to use current interfaces to build new applications, and
previous investments in development, training and tools should hold their value.

Current SOAP and REST based ACE programming models are no longer supported in SQL Azure, but building
custom services with ADO.NET Data Services does provide a relatively simple solution for those requiring REST
access to their SQL Azure data. For REST based programming model users, who simply require non-relational
structured data storage, Windows Azure storage should prove to be an adequate solution.

Visual Studio can be used to create and modify applications for SQL Azure. Additionally, for developing new
applications, ASP.NET controls and tools are a useful solution. Web based management tools, to access and
manage data in the cloud, and tools and documentation supporting further programming languages, are expected
to be introduced in the near future. 

Various Models Details in working with SQL Azure:
Service Providing Model
*Each account has zero or more logical servers
Provisioned via a common portal
Establishes a billing instrument
*Each logical server has one or more databases
Contains metadata about database & usage
Unit of authentication, geo-location, billing, reporting
Generated DNS-based name
*Each database has standard SQL objects
Users, Tables, Views, Indices, etc
*Unit of consistency

 Connection Model:
*SQL Azure exposes native SQL Server TDS protocol
*Use existing client libraries
*Client libraries pre-installed in Windows Azure roles
*Support for ASP.NET controls
*Applications connect directly to a database
Cannot hop across DBs (no USE)

Connecting to SQL Azure
SQL Azure connection strings follow normal SQL syntax
*Applications connect directly to a database
"Initial Catalog = <db>" in connection string
No support for context switching (no USE <db>)
*Encryption security
Set Encrypt = True, only SSL connections are supported
TrustServerCertificate = False, avoid Man-In-The-Middle-Attack!
*Format of username for authentication:
User ID=user@server;Password=password;...
*Setup your firewall rules first!
 Security Model

•Uses regular SQL security model
•Authenticate logins, map to users and roles
Authorize users and roles to SQL objects
•Support for standard SQL Auth logins
•Username + password

this all about the sql Azure role in Cloud Computing..

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