DEFINITION BASIS DATA
1. The Definition of databases:
a. A group of data file in disk magnetic, optical disk or depository of other sekunder
b. Inwrought collection of datas which each other is interconnected the than an enterprise ( company, government institution or private sector )
1. Manufacturing business -> planning data production, acctual data production, data ordering of material, etc
2. Hospital -> data of patient, doctor, nurse, etc

DATABASE MANAGEMENT SYSTEM
1. Corps or database aliance with software application being based on database
2. This programs application is used to access and maintenance of database
3. Especial target of DBMS is provide an efficient and easy environment for the usage of, withdraw and depository of data and information

BIT, BYTE, FIELD
1. Bit -> the representing part of containing smallest data of value 0 or 1
2. Byte -> the collection of bits which of a kind
3. Field -> a group of byte-byte which of a kind, in databases used by attribute term

ATRIBUT/FIELD
1. The Representing of nature or characteristic from an entitas providing to detail of clarification about entitas
2. An relationship can also have attribute
The Example of Attribute :
a) STUDENT: NIM, NAME, ADDRESS
b) CAR: PLATENUMBER, COLOUR, TYPE, CC

ATRIBUT TYPES
1. Single vs multivalue
Single -> just can fill at most one value
Multivalue -> can fill with interest from one value with same type
2. Atomic vs komposisi
Atomic -> indiscrete into smaller attribute
Composition -> the representing aliance from some smaller attribute

ATRIBUT TYPES (2)
1. Derived Attribute
The attribute which is value can be yielded from other attribute value, for example -> yielded age of attribute of birthdate
2. Null Value Attribute
The attribute which don’t have value to an record
3. Mandatory Value Attribute
The attribute which must have value

RECORD/TUPLE
1. Representing an data line in a certain relationship
2. The Consist of attributes corps where attributes of interaction to inform entitas / relationship completely

ENTITAS/FILE
1. File is represent colection of record which of a kind and have same element, the same attribute but different each other its data of him.
2. Type File
3. In application process, file can be categorized as follows:
a) File Mains
b) File Transaction
c) File Report
d) File History
e) File Protector
f) File Job

DOMAIN
The Domain represent collection of values enabled to stay in one or more attribute. Every attribute in once databases of relasional defined by an domain

DATA ELEMENT KEY
Key is element of record weared to find the record when accessing or can also used to identify every entity/record/baris.

1. Superkey represent one or more attribute from an table of able to be used to identify entityty / record of tables uniquely ( don’t all attribute can become superkey)
2. Cadidate Key is super key with minimum attribute. Candidate key may not contain attribute of other tables so that key candidate beyond question superkey but not yet of course on the contrary.
3. Primary Key
One of the attribute of key candidate can be selected / determined to become primary key with three criterion as follow:
1. The Key more natural to used as reference
2. The Key more simple
3. The Key well guaranted him

a) Alternate Key is attribute of key candidate which is not chosen become primary key.
b) Foreign Key represent any attribute subjecting to key primary at other tables.
c) Foreign key will happened at one particular relationship owning one to many kardinalitas ( one to many) or many to many ( many to many). Foreign key usually always put down at tables of which is flange to many.
d) External Key represent an attribute lexical ( or gathering of lexical attribute) which is values always identify one object of instance

ERD (ENTITY RELATIONSHIP DIAGRAM)
1. ERD is a network model using wording which is kept in system abstractionly.
2. Difference between DFD and ERD :
a) DFD represent a function network model to be executed by system
b) ERD represent data network model emphasizing at and structure of data relationship

ELEMEN IN ERD
1. ENTITY
At ER Diagram of Entity depicted with square form of length. entity is something that there is in real system and also abstraction where on file data or where there are data.
2. Relationship
At ER relationship Diagram can be depicted with a lozenged. Relationship is natural relation that happened between entitas. Is general called with elementary vb. so that facilitate to read of relationship.
3. Relationship Degree
Relationship Degree is the amount of entitas participating in one relationship. Degree of which is often weared in ERD.
4. Attribute
Attribute is the nature or characteristic of each and also entitas of relationship
5. Kardinalitas showing optimum of tupel able to relate to entitas at other entitas
Derajat relationship
1. Unary Relationship is model of relationship that happened between entity coming from entity same.
2. Binary Relationship is model of relationship that happened between 2 entitas..
3. Ternary Relationship Representing relationship between instance from 3 type of entitas unilaterally

KARDINALITAS
Available 3 cardinalities relationships which is
1. One to One : Relation storey level one to one expressed with one occurence at first entitas, only having one relation with one occurence at second entitas conversely.
2. One to Many atau Many to One : Subjective zoom one to there are many is same with many to one pending of tenor which that relationship is seen. To one instance on entities first gets to have many relationship with instance on entities secondly, if contrariwise one instance on entities just secondly gets to have connection with one instance on entities is first.
3. Many To Many : Happening if each event on one entities has a many relationship with event on another entities.

NOTATION IN ER-DIAGRAM
Symbolic notation diagrammatically ER is
1. Length square declare for entities gathering
2. Circle declares for attribute
3. Explain rhomb relationship gathering
4. Lining as connecting as among relationship gathering with entities gathering and
5. Entities Gathering with its attribute