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A database is a structured collection of records or data that is stored in a computer system. The structure is achieved by organizing the data according to a database model. The model in most common use today is the relational model. Other models such as the hierarchical model and the network model use a more explicit representation of relationships

increase their speed

common kind of index is a sorted list of the contents of some particular table column, with pointers to the row associated with the value

These headers tell us which web server you were trying to contact.  If that seems odd, bear in mind that many web sites can be "hosted" on a single server, so when the request is received it needs to know which web site you were attempting to access

The request method is usually either "GET" or "POST".  Basically if you fill in and submit a form on a web page it might generate a POST request (or it might be "GET"), whereas if you just click on a link, or activate one of your browser's "bookmarks" or "favourites", then the request method will always be "GET". Therefore, if it's "POST", we can tell that a form was definitely submitted.  The contents of the form would appear here, and there would also be some "Content-" headers describing the data. Web browsers generate two kinds of "POST" data: either "multipart/form-data", which is used when uploading files to a web server, or the more common "application/x-www-form-urlencoded".

The "referer" header tells us which document referred you to us - in essence, if you followed a link to get to this page, it is the URL of the page you came from to get here.

An assembly can be a single file or it may consist of the multiple files. In case of multi-file, there is one master module containing the manifest while other assemblies exist as non-manifest modules. A module in .NET is a sub part of a multi-file .NET assembly

The .NET assembly is the standard for components developed with the Microsoft.NET. Dot NET assemblies may or may not be executable, i.e., they might exist as the executable (.exe) file or dynamic link library (DLL) file. All the .NET assemblies contain the definition of types, versioning information for the type, meta-data, and manifest. The designers of .NET have worked a lot on the component (assembly) resolution.

design pattern is a widely accepted solution to a recurring design problem in OOP a design pattern describes how to structure classes to meet a given requirement provides a general blueprint to follow when implementing part of a program does not describe how to structure the entire application does not describe specific algorithms focuses on relationships between classes

design patterns: make you more productive help you write cleaner code Observer and Singleton are just two of the many available if you like design patterns, try these resources: GoF book -- Design Patterns: Elements of Reusable Object-oriented Software design pattern examples in Java, see Design Patterns in Java Reference and Example Site

learn what a design pattern is

3. JSON Class hinting ¶ There are only simple data types defined in JSON. To overcome this problem in a JSON compatible way a special property for objects is introduced. {"__jsonclass__":["constructor", [param1,...]], "prop1": ...} The object is then instantiated using the constructor, passing in the parameters. Once constructed the properties (prop1, ...) will be applied.

To give the serverside peer a chance to send messages to the client side peer, the client side peer may reopen communication by sending an empty HTTP POST.

--> {"method": "postMessage", "params": ["Hello all!"], "id": 99} <-- {"result": 1, "error": null, "id": 99} <-- {"method": "handleMessage", "params": ["user1", "we were just talking"], "id": null} <-- {"method": "handleMessage", "params": ["user3", "sorry, gotta go now, ttyl"], "id": null} --> {"method": "postMessage", "params": ["I have a question:"], "id": 101} <-- {"method": "userLeft", "params": ["user3"], "id": null} <-- {"result": 1, "error": null, "id": 101}

A pattern must explain why a particular situation causes problems, and why the proposed solution is considered a good one. Christopher Alexander describes common design problems as arising from "conflicting forces" -- such as the conflict between wanting a room to be sunny and wanting it not to overheat on summer afternoons. A pattern would not tell the designer how many windows to put in the room; instead, it would propose a set of values to guide the designer toward a decision that is best for their particular application. Alexander, for example, suggests that enough windows should be included to direct light all around the room. He considers this a good solution because he believes it increases the enjoyment of the room by its occupants. Other authors might come to different conclusions, if they place higher value on heating costs, or material costs. These values, used by the pattern's author to determine which solution is "best", must also be documented within the pattern. A pattern must also explain when it is applicable. Since two houses may be very different from one another, a design pattern for houses must be broad enough to apply to both of them, but not so vague that it doesn't help the designer make decisions. The range of situations in which a pattern can be used is called its context. Some examples might be "all houses", "all two-story houses", or "all places where people spend time." The context must be documented within the pattern. For instance, in Christopher Alexander's work, bus stops and waiting rooms in a surgery are both part of the context for the pattern "A PLACE TO WAIT."

A Voyage to Functional Programming in F#

Finally I settled on F#. Both LISP and F# are belong to functional programming (FP) paradigm.Functional programming is a complete different paradigm from imperative (and OO) programming.I found it terse as well yet I can understand it (though some of the concepts are new to me).The advantage is it can use .NET Framework. Thus it gives me a break from OOP and yet taps the power from the familiar .NET Framework.Therefore I decided to dive into it to seem whether functional programming can deliver its claims in terms of productivity and expression power.I would like to share my findings in this blog to those interested in learning functional programming.