NORMALIZATION

Labels: - Thursday, March 26, 2009

Normalization process is process to obtain relationship scheme property’s that is nicely becomes higher normal form so that conditions under this fulfilled:

  • loop of data which is not necessarily. Redundancy cannot be eliminated at all because good for integrity referential, but redundancy in optimalisation can. For data amounts which are not too much might not too influential in the case of usage hard disk. But imagined if there is thousands, even millions of redundancy, possibly will hardly having an in with space usage.
  • Eliminates anomaly. Anomaly basically is un-consistency (inconsistency). Takes example there are commutation of name of from Bank “Maju” becomes Bank “Maju Terus” counted 4 records. If commutation of name of only done at one of record only, hence happened un-consistency that is one relationship bank numbers with 2 name of different bank.

Decomposition tables of can lessen the redundancy and eliminates anomaly.

Scheme through normalization process has advantages as follows:
a. minimization of Storage measure needed to by data storage.
b. minimization of Risk inconsistency data at data base.
c. Minimization possibility that renewal anomaly.
d. Maximizes data structures stability.

Normal form

Purpose of normalization process is convert relationship to become higher normal form. There is having immeasurable level of normal form, that is :
a. First normal form (1NF)
b. Second normal form (2NF)
c. Third normal form (3NF)
d. Normal Form Boyce-Codd (BCNF)
e. Fourth normal form ( 4NF)
f. Fifth normal form ( 5NF)


First normal form to eliminate plural valuable attribute. Second normal form to eliminate partial dependence. Third normal form to eliminate transitive dependence. Normal Form Boyce-Codd to eliminate anomaly remains caused [by] functional dependence. Fourth normal form to eliminate plural value dependence. Fifth normal form to eliminate anomaly remains.

Three normal forms firstly relates to functional dependence. Meanwhile fifth and fourth form related to redundancy caused by dependence many values ( multi-valued dependencies).

First Normal Form

First normal form is equivalent with definition of model relational. Relationship is first normal form (1NF) if all its(the attribute values was simple ( non composite).

Second Normal Form

Having second normal form is rule must have is in the form of first normal ( 1NF), and all attributes is not main must hinge is functional fullness at relationship lock.

Relationship at second normal form storage should not facts about part of relationship lock. Eliminating second normal form is parsial dependence and still having anomaly’s that is practically in acceptable.

Third Normal Form

Normal form third has rule must have is in the form of normal second ( 2NF) and relationship may not load functional dependence among attributes is not main.

Normal form third eliminates transitive dependence, initially normal form third is thought as a form of normal of top / very end. But then detectable stronger normal form that is normal form Boyce-Codd.

Normal Form Boyce-Codd ( BCNF)

BCNF has rule that is each main attribute hinged is functional fullness at each lock where the lock is non part of his (its. Relationship is BCNF (optimal) if every relationship attributes determinant was locked relationship. Relationship is BCNF (optimal) if whenever facts is kept about some attributes, hence this attributes is one relationship locks. BCNF can have lock multiple. Important property of BCNF is relationship doesn't have information which redundancy.

Fourth Normal Form

Relationship in the form of fourth normal (4NF) if relationship in BCNF and didn't contain dependence many values. To eliminate dependence many values out of one relationship, we divide relationship to become two new relationships. Every relationship contains two attributes having relationship many values.

Fifth Normal Form

Fifth normal form (5NF) deals with property so-called join without existence of loss of information (lossless join). Fifth normal form (5NF) also is called as PJNF (normal projection-join of form). This Cases very rare emerges and difficult to be detected practically.

SINGLE LINKED LIST WITH LIFO METHOD AND FIFO

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LIFO - LAST INDIUM FIRST OUT

Making method of linked list where data entering is most recently is earliest secretary data
If linked list is made with LIFO method, hence addition of node happened rear.

INITIAL DECLARATION

TYPE
Point = ^RecPoint;
RecPoint = Record
Isi : TipeData;
Next : Point;
End;
VAR
Head, Tail, Now : Point;

PROCEDURE INSERT LIFO

PROCEDURE INSERT (element: data type);
VAR Now: Point;
BEGIN
New (Now);
Now^.Isi := element;
if Head=Nil then
Now^.Next :=Nil;
Else
Now^.Next := Head;
Head: =Now;
End;

PROCEDURE INSERT FIFO

PROCEDURE INSERT (element : data type);
VAR Now: Point;
BEGIN
New (Now);
if Head=Nil then
Head: =Now
else
Tail^.Next :=Now;
Tail: =Now;
Tail^.Next:=nil;
Now^.Isi:= Element;
End;

COMPUTER NETWORK

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Classification of Computer network

Criterion to classify computer network based on computer network distance one with other
Distance is important thing as measure classification because required technique - technique which differs in distance different
1. Local Area Network ( LAN)
2. Metropolitan of Area Network ( MAN)
3. Wide Area Network ( WAN)

CLIENT SERVER

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1. Standalone (one-tier)



At all these architecture of processor done at mainframe. Application code, data and all System Components placed and implemented at host. Although computer client used to access mainframe, there is no processor happened at this machine, and because they “dump-client” or “dump-terminal”. This model type, where all processor happened centrality, known as berbasis-host.

2. Client/Server ( two-tier)

In modeling client/server, processor at an application happened at client and server. Client/server it is typical a the application of two-tier with many client and a server connected through a network. Application placed at computer client and machine database implemented at server distance - far. The application of client releases request to database which sends again data to its(the client. In client/server, client-client which is smart accountable for part of application which interaction with user, including business logic and communications with database server. Duty types happened at client is :
  • User interface
  • interaction of Database
  • Retrieval and modification of data
  • A number of business orders
  • Mistake handling
3. Three-tier / Multi-tier



Model three-tier or multi-tier developed to answer limitation at architecture client/server.
In modeling this, processor is propagated in three layers (or more if it is applied architecture mortifier).

Third layer in this summing up each architecture is special function of tonality. That is:
Presentation service (level of client)
Business service (middle store)
.Data service (level of data source)

Presentation service or user interface logic placed at machine client. Business logic released from code client and placed in middle store. Data service layer contains server
database. Every level in modeling three-tier to stay at stand alone computer. Model concept three-tier is model is dividing function of tonality into layers, application – application gets scale ability, new, and security and safety.

VISUAL OF BASIC 6.0

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Visual of Basic basically is a computer programming language. Programming language is command - command or instruction - intrusions understood by computer to do duty - certain duty.

Visual of Basic besides conceived of programming language, also is conceived of supporting facilities (tool) to yield program - application program bases on windows.

Some abilities or benefit from Visual Basic between it like:
  • To make application program bases on windows
  • To make object - program assistant object like for example ActiveX, file help, the application of internet etcetera.
  • Tests program ( debugging) and yields final program ended EXE is having the character of executable.

EXCESS OF VISUAL MICROSOFT OF BASIC 6.0
  • Can build multi project in simulation, and can build the application of database client / server performance function of capable: 1. Access Microsoft SQL Server 2. Pick aback remote Automation and D com 3. Uses visual of Query and planning connection network 4. Pick aback transact SQL Debug and remote object data 20
  • Provides many peripheral to designing the application of web
  • Has form of expensive graphic design compared to system under Dos.
  • Can be application by using multimedia peripheral

WEAKNESS OF VISUAL MICROSOFT OF BASIC 6.0:
a. For this systems development costs money a real big.
b. In applying requires expensive hardware compared to with system which under Dos.
c. Result of independent abnormal compiler without existence of operating system windows.

OBJECT IN SQL SERVER 2000

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1. Database
Contains objects applied to represent, depositor data, and access data.

2. Tables
Depositor lines or record interacting data one another.

3. Diagrams Data
Graphically presents database, so that manipulation can without having to
Uses command Transact-SQL.

4. Index
Addition files increasing speed of access from table’s line

5. View
Provides way of view data differing from entangles one or more tables.

6. Stored procedure
Programs Transact-sql kept in server to implement duty – duty Which has been determined?

7. Function

Gathering of command containing input or doesn't apply input either one or Multiple and releases value either in the form of scalar and also tabular (be in the form of tables). Ex: function of SUM to add some values. Function Of DATE DIFF for determines difference between two date. Function @@ SERVER NAME for gets name from server. And functions which we are create x' self.

8. Trigger
a type procedure kept and implemented in Event-driven if Certain operation done at tables.

IMPLEMENTS QUERY
Before implementing Query, command SQL which we earn in coequal based on regulation of Syntax with clicks button (√ ) . While to implement applies button ( >).

DATA TYPE

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DATA TYPE

Data type applied to define data type owned by server object like Variable, parameters, column ( field). Data which can be packed into our database it is of course all kinds. In MS-SQL Server 2000 supporting assorted of data type.

NUMERIC

1. bigint
Integer value with value from - 2^63 (- 9223372036854775808)
to 2^63-1 ( 9223372036854775807).

2. int
Integer value with value from - 2^31 (- 2,147,483,648) to 2^31 - 1 ( 2,147,483,647).

3. small int
Integer value with value out of 2^15 (- 32,768) until 2^15 - 1 ( 32,767).

4. tinyint
Integer value with value from 0 to 255.

5. bit
Integer value with value 1 or 0.

6. Decimal and Numeric
Numeral with permanent accuration from - 10^38 + 1 to 10^38 – 1.

MONEY

1. money
Data with value currency - 2^63 (- 922,337,203,685,4775808)
through 2^63 - 1 (+ 922,337,203,685,4775807)

2. Small money
Data with currency value - 214,7483648 through + 214,7483647

NUMERIC PRECESSION

1. Float
Precession number from - 179E + 308 until 179E + 308.

2. real
Precession number from - 340E + 38 until 340E + 38.

DATE TIME

1. date time
Date and time from January 1, 1753, until December 31, 9999,
with accuration to 333 mills second

2. smalldatetime
Date and time from January 1, 1900, until June 6, 2079, with accuration one minutes.

STRINGS

1. Char
Field contains character of the size permanent length with maximum length 8,000 characters.

2. varchar
Field contains character with erratic measure length with maximum length 8,000 characters.

3. Text
Variable contains character with footage to 2^31 - 1 ( 2,147,483,647) character.

COMPUTER SCIENCE ARTICLE

Labels: - Friday, March 20, 2009

SQL SERVER 2000

Microsoft SQL Server 2000 is one of pledge product Microsoft for database server. Ability in management data and amenity in operation makes DMBS (Database Management System) this becomes choice of the databases administrator.

There is two ways to process our database in SQL Server that is passing:

1. Windows Enterprise manager
2. Windows Query Analyzer

FOLLOWING IS WINDOWS DISPLAY SQL SERVER 2000 :


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