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MARS (Multiple Active Resultset)

MARS is a new feature introduced in ADO.NET 2.0 which enables having a connection string to execute multiple queries and obtain active readers concurrently. Best suitable for master detail query scenario in applications. This feature works only with SQL Server 2005. By default SQL connection objects are not enabled to support the feature and requires multiple activeresultset key to be set to true.

SQL server 2005 supports 5 types of transaction isolation levels
1. Read Committed
2. Read Uncommitted
3. Repeatable Read
4. Serializable
5. Snapshot Isolation

In case of snapshot Isolation when a transaction selects a record, DB engine stores in a temp database and allows the transaction to work on them.

When a transaction tries to commits, db engine verifies whether the initial version obtained by the transaction, matches with the current version of the database and succeeds with a commit if both match which otherwise causes update conflict error being thrown. MARS works with the help of SQL Server snapshot isolation.

Windows Communication Foundation (WCF)

Windows Communication Foundation (WCF) is the latest service execution environment from Microsoft that enables you to seamlessly expose CLR types as services and consume services as CLR types. WCF is a unified programming model that combines the best of breed features from XML Web Services, .NET Remoting, MSMQ, and COM+ into an integrated platform that is completely based on a set of open industry standards. Because of that, WCF provides interoperability between services, and it promotes productivity, including the essential off-the-shelf plumbing required by almost any application.

To start working on WCF you would need

1. Visual Studio .Net 2005


2. Microsoft Pre-Release Software Microsoft .NET Framework 3.0


3. Microsoft Windows Software Development Kit (Web) for RC 1 of Windows Vista and .NET Framework 3.0 Runtime Components


4. Microsoft Visual Studio Code Name Orcas Community Technology Preview Development Tools for .NET Framework 3.0


5. Microsoft Visual Studio 2005 Extensions for Windows Workflow Foundation Release Candidate 5

SQL CLR Integration Support

SQL Server 2005 is now an ORDBMS database. In order to provide the managed support to the database, SQL server hosts CLR into theprocess and provides and extent programming capabilities to TSQL.

The following are the Database objects which can be created in .NET Environment

• Stored Procedures
• Functions
• Triggers
• User Defined Aggregates
• User Defined Types

SslStream Class for .NET 2.0

Provides a stream used for client-server communication that uses the Secure Socket Layer (SSL) security protocol to authenticate the server and optionally the client.

An SslStream instance transmits data using a stream that you supply when creating the SslStream.

When you supply this underlying stream, you have the option to specify whether closing the SslStream also closes the underlying stream. Typically, the SslStream class is used with the TcpClient and TcpListener classes. The GetStream method provides a NetworkStream suitable for use with the SslStream class.

CLR Profiler

Using CLR Profiler you can

• obtain useful information about the execution, allocation, and memory consumption of your application
• identify code that allocates too much memory, causes too many garbage collections, and holds on to memory for too long
• See who allocates what on the managed heap
• See which objects survive on the managed heap
• See who is holding on to objects
• See what the garbage collector does over the lifetime of your application

Results of profiling are stored in log files.
You can view these files in various ways by using the view menus in CLR Profiler to display the corresponding graphs.

Shallow and Deep Copy in .NET

A shallow copy is when the values in an object’s fields are copied but what the fields refer to is not copied. For example, if an object has a field that refers to a string and you make a shallow copy of the object, then you have two objects that refer to the same string.

Shallow copy can be done by calling MemberwiseClone() method on that object.

A deep copy is when you make a copy of what an object’s fields refer to.
So if you made a deep copy of an object that has a field that refers to a string, you’d be creating a new object and a new string—the new object would refer to the new string. The important thing to note about a deep copy is that the original and the new object share nothing; modifying one object has no effect on the other object.

We should not call MemberwiseClone for deep copy, but rather, allocate a new object and implement your deep copy semantics

Session Data Management Tool

Passing session data from one page to another web page is no big deal in an ASP.NET application. For example, the following code stores data on an internet session using the .NET web session provided by the .NET Framework:

Session[“username”] = _username;
Session[“userid”] = _userid;

If the user navigated to a different page, the data is already available on the server and hence there is no need to pass these session data via a query string.

By default, the session data is stored in memory of the server process, which makes it very efficient. If you want to load balance your application using several servers or you want to reboot the server machine without any major impact on the current users, you can modify the web.config file of your application so that the session data will be stored in a SQL server database or in the memory of a Microsoft session state server instance.

Obviously you would always want to do more than the current tools allows you to do. You would like to share session data among different applications. Also some of the applications might be running on machines without the .net framework, and some of them not even web application. Obviously we are only dealing with applications we trust so there is no security issue here.

The .NET framework built-in session is not suitable for a few reasons
- It does not allow you to share session data across different applications
- Its only available to .net web applications, other applications cannot use it.
- Using SQL server option data is saved in the database. However there is no way for you to view the data outside your application, because it is stored in binary format.

So the need arises to have a simple, reliable and efficient session tool that does not have the above shortcomings. You can have any number of applications running on one or more servers all sharing the same session data.

Cool Tips on ASP.NET 2.0

ASP.NET 2.0 is filled with great new features. Lets explore some of the great tips and tricks that show off some of the awesome capabilities of ASP.NET 2.0

Cross Page Postback between pages
Its just a property now for a button.

ValidationGrops
You ca now optionally validate depending on which button on the page is pushed. Group the validations rules into "groups" and that’s it.

Wizard control
That’s all you wanted for your complex pages for capturing data. No more handling panels or div tags.

Dynamic Image Server control
You can now have a databinding photo-album where all images are stored in the database and bound to the DynamicImage control within a DataList template. The best part is, it does not require any code.

URL Rewriting
This is the most sought out service for any e-commerce application. Just use the UrlMapping Service

SiteCounter
Use this service to efficiently log and record usage patterns on a site and this includes your page views, clicks on links, ad banner click and impressions tracking.

FileSystemProvider
For all the CMS developers, show you can store .aspx pages inside your own custom database (with code and code-behind) and how you can configure ASP.NET to pull and execute the content from places other than the file-system.

Membership & Roles
Using the ASP.NET Forms Authentication architecture and Membership and Role Management system to provide authentication/authorization to non-ASP.NET pages/resources.
So try classic ASP site with login/role management support using ASP.NET and also show PHP or JSP protected using ASP.NET as well.

Amazing Client Script Goodies
Show automatically maintaining scroll positions during postback, controlling default buttons and focus, programmatically setting focus on controls on the server, and easily handling client-side click events using server control buttons.

RSS Blog Reader
Build a simple RSS Blog reader from scratch using the new XmlDataSource control, DataList server control and the new XPath binding support for hierarchical data structures. Well do all this with a new ASP.NET reader working off of this blog.

Build Providers
Talk about the ability to add declarative types into your "code" directory and have them automatically compiled as part of your website.

"No Compile" Pages
Enable Administrators to lock down what code is allowed or not for portions of a site.