Glossary

An Explanation of Terminology

.NET Architecture

Microsoft defines Microsoft .NET as a set of Microsoft software technologies for connecting information, people, systems, and devices. To optimize software integration, the .NET Framework uses small, discrete, building-block applications called Web services that connect to each other as well as to other, larger applications over the Internet.

The .NET Framework has two key parts:

ASP.NET is an environment for building smart client applications (Windows Forms), and a loosely-coupled data access subsystem (ADO.NET).

The common language runtime (CLR) is the core runtime engine for executing applications in the .NET Framework. You can think of the CLR as a safe area--a "sandbox"-- inside of which your .NET code runs. Code that runs in the CLR is called managed code

ADO.NET

The data access component for the .NET Framework. ADO.NET is made of a set of classes that are used for connecting to a database, providing access to relational data, XML, and application data, and retrieving results.

assembly

A compiled representation of one or more classes. Each assembly is self-contained, that is, the assembly includes the metadata about the assembly as a whole. Assemblies can be private or shared.

Private assemblies, which are used by a limited number of applications, are placed in the application folder or one of its subfolders. For example, even if the client has two different applications that call a private assembly named formulas, each client application loads the correct assembly.

Shared assemblies, which are available to multiple client applications, are placed in the Global Assembly Cache (GAC). Each shared assembly is assigned a strong name to handle name and version conflicts.

client load balancing

A mechanism that distributes new connections in a computing environment so that no one server is overwhelmed with connection requests.

code access security (CAS)

A mechanism provided by the common language runtime through which managed code is granted permissions by security policy; permissions are enforced, limiting the operations that the code will be allowed to perform.

common language runtime (CLR)

The common language runtime (CLR) is the core runtime engine in the Microsoft .NET Framework. The CLR supplies services such as cross-language integration, code access security, object lifetime management, and debugging support. Applications that run in the CLR are sometimes said to be running "in the sandbox."

connection failover

A mechanism that allows an application to connect to an alternate, or backup, database server if the primary database server is unavailable, for example, because of a hardware failure or traffic overload.

connection pooling

The process by which connections can be reused rather than creating a new one every time the data provider needs to establish a connection to the underlying database.

connection retry

Connection retry defines the number of times the data provider attempts to connect to the primary and, if configured, alternate database servers after the initial unsuccessful connection attempt. Connection retry can be an important strategy for system recovery.

global assembly cache (GAC)

The part of the assembly cache that stores assemblies specifically installed to be shared by many applications on the computer. Applications deployed in the global assembly cache must have a strong name to handle name and version conflicts.

isolation level

A particular locking strategy employed in the database system to improve data consistency.The higher the isolation level number, the more complex the locking strategy behind it. The isolation level provided by the database determines how a transaction handles data consistency.

The American National Standards Institute (ANSI) defines four isolation levels:

Read uncommitted (0)

Read committed (1)

Repeatable read (2)

Serializable (3)

load balancing

See client load balancing.

locking level

A database operation that restricts a user from accessing a table or record. Locking is used in situations more than one user might try to use the same table or the same time. By locking the table or record, the system that only one user at a time can affect the data.

managed code

Code executed and managed by the .NET Framework, specifically by the CLR. Managed code must supply the information necessary for the CLR to provide services such as memory management and code access security.

namespace

A logical naming scheme for grouping related types. The .NET Framework uses a hierarchical naming scheme for grouping types into logical categories of related functionality, such as the ASP.NET technology or remoting functionality. Design tools can use namespaces to make it easier for developers to browse and reference types in their code. A single assembly can contain types whose hierarchical names have different namespace roots, and a logical namespace root can span multiple assemblies. In the .NET Framework, a namespace is a logical design-time naming convenience, whereas an assembly establishes the name scope for types at run time.

Performance Monitor

A tool in the Windows SDK that identifies areas in which performance problems exist.

stream

An abstraction of a sequence of binary or text data. The Stream class and its derived classes provide a generic view of these different types of input and output.

strong name

A name that consists of an assembly's text name, version number, and culture information (if provided), with a public key and a digital signature generated over the assembly. Assemblies with the same strong name should be identical.

unmanaged code

Code that is executed directly by the operating system, outside of the CLR. Unmanaged code includes all code written before the .NET Framework was introduced. Because it outside the .NET environment, unmanaged code cannot make use of any .NET managed facilities.