DATABASE DEFINITIONS
Database is a group of on file data in disk magnetic, disk optical or is depository of other sekunder. Inwrought collection of data-data which each other is interconnected the than a enterprise (company, governmental institution or private sector). Example:
- Manufacturing business (production planning data, data produce aktual, data ordering of material, etc)
- Hospital (patient data, doctor, nurse, etc)
DATABASE MANAGEMENT SYSTEM
Database management system represent database aliance or corps with software of application being based on database. This application programs is used to access and look after database. Especial target of DBMS is to provide a efficient and easy environment for the usage of, to withdrawal and is depository of information and data.
BIT, BYTE, FIELD
- Bit representing part of containing smallest data of value 0 or 1.
- Byte representing corps of beets which of a kind.
- Field representing a group of byte-byte which of a kind, in data bases used by attribute term.
ATTRIBUTE OR FIELD
Attribute is the nature or characteristics of an entity that provides provide detail on these entities. A relationship can also have attributes. Example attributes:
1. STUDENTS: NIM, NAME, ADDRESS
2. CAR: NOMOR_PLAT, COLOR, TYPE, CC
ATTRIBUTE TYPES
• Single attribute vs multivalue attribute
Single attribute is an attribute that can only be filled at most one value.
Multivalue attribute is an attribute that can be filled with more than one value with the same type.
• Atomic vs composition
Atomic attribute is an attribute that can not be divided into smaller attributes.
Composite attribute is a combination of several attributes of a smaller.
• Derived attribute is an attribute whose value can be derived from the value of other attributes, such as age that resulted from birth date attribute.
• Null Value attribute is an attribute that has no value to a record.
• Value attribute is a mandatory attribute that must have a value.
RECORD / TUPLE
Record is a data line in a relationship. Record consists of a set of attribute-attribute where the attribute is an attribute-related entity or to inform the full relationship.
ENTITY / FILE Entity is the object or objects in a certain mini world represented in the database. Entity can be:
1. Things that have physical (people, cars, houses, etc.)
2. think that there are conceptual (enterprise, employment, discipline, etc.)
File is a collection of similar records and have the same elements, the same attributes but different data values. In processing applications, files can categories with several types as follows:
- Master File
- Transaction Files
- File Reports
- File History
- File Protection
- File Work
DOMAIN
Domain is the set of values that are allowed to reside in one or more attributes. Each attribute in a database relational is defined as a domain
KEY DATA ELEMENT
Key elements of record which is used to find these records at the time of access, or can also be used to identify each entity / record / line.
ERD
Entity relationship is a network that uses the order of the data stored in the abstract of the system. Entity-relationship model consists of elements of the entity and entity-relationship between these entitiy.
Component Entity Relationship :
1. Entity, a collection of object or something that can be identified or can be unique.
Collection of similar entities called entity set.
2. Relationship, the relationship between one entity or more.
3. Attribute, the collection of data elements that form a entity
4. Relationship Degree is the number of entities participating in a relationship. Degree which is often used in the ERD
Degree of relationship:
• Unary Relationship
model is the relationship between the entity originating from the same entity set.
• Binary Relationship
model is the relationship between 2 entities.
• Ternary Relationship
is a relationship between the instance of 3 types of entities are unilateral.
5. Cardinalitas tupel indicates the maximum number that can be entity with entities on the other entity.
There are 3 kardinalitas relations, namely :
• One to One: Level one to one relationship with the one stated in the entity's first event, only had one relationship with one incident in which the two entities and vice versa.
• One to Many or Many to One: Level one to many relationship is the same as the one to many depending on the direction from which the relationship dilihat.Untuk an incident on the first entity can have any relationship with many incident on the second entity, if the one incident on the entity the second can only have one hubugan with the incident on the first entity.
• Many To Many: if any incident occurs in an entity most have relationships with other entities in the incident.
Referensi :
1. ER Ngurah Agus Sanjaya. Slide Part 5 - DATABASE DAN ER-DIAGRAM.
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