DATA BASIS DEFINITION

Data basis definition:
Data’s agglomerate gathering (archives) one that interaction that at organization in such a way that face coming can utilize back at a fast pace and edge out. Interrelates data set that is kept collectively in such a way face and without repeat (redundancy) one that not necessarily, for meeting requirement sort. File bulk / table / interrelates archives that is kept in given storage media


To the effect Data Basis Exploit

1. Speed and easy (Speed)
Namely that data basis user can:
- keeping data
- do changing / manipulation to data
- featuring data back
with faster and easy than by ordinary (well manual or even electronic).

2. Stored Spatial efficiency (Space)
With our data basis can do redundancy’s amount emphasis (repeat) data, well by applying a number coded or with make relationships among agglomerate data which interaction.

3. Accuracy (Accuracy)
That data corresponds to order and particular limitation by utilize coded or formation relationship among data stands up with order implement / limitation( constraint ) data type, domain is data, data uniqueness etcetera.

4. Availability of (Availability)
That data can be accessed by each user that needs, with network adjustment of technology and does move / data deletion already don't be utilized / statute bared to economize storage room.

5. Equipment (Completeness)
That data that is brought off everlastingly fledged good relative to user the need and also to time, by undertaking data row increases or even do changing structures on data basis; namely with adds field on table or adds new table.

6. Security (security)
That data that gets secrecy or process that vital not fells to person / user that don't deserve, namely with account's purpose (username and password) and applies access right distinction each user to data who can be read or process who can be done.

7. Togetherness (Sharability)
So that the data is managed by the system supports multiuser environment (many users), with guard / avoid the emergence of new problems such as data inconsistencies (due to data changes made by multiple users in the same time) or the condition of deadlock (because there are many users waiting for the mutual to use the data).


SYSTEM'S DATABASE MANAGEMENT
Are system that specially been made to make easy user in bring off data basis. This system is made to settle proceedings system weakness that gets file basis. On approaching that gets file basis, generally system scheme is gone upon on individual's requirement user, don't base the need a number user. Every time available new requirement of an user, immediate requirement deciphered into computer program. Accordingly, very likely each application program set down alone data. In the meantime any chance same data also available on other files that utilized by other application program.
To the effect main DBMS IS provide an easy and efficient environment for purpose, pull and laid up data and information

BIT, BYTE, FIELD
Bit  constitute a part data most meaty little appreciative 0 or 1
Byte  bulk of bit bit that a sort
Field  a group byte byte that a sort, in data basis utilized by attribute terminology



ATTRIBUTE / FIELD
Constituting character or characteristic of an entitas that provide detail's explanations about entities that. A relationship can also have attribute.
Attribute example:
• COLLEGE STUDENT: NIM, NAME, ADDRESS
• CAR: NOMOR_PLAT, COLOR, TYPE, CC

ATTRIBUTE TYPES
• Single vs multivalue
• Single  just can be filled at most one point
• Multivalue  can be filled by more than one point with same type of
• Atomic vs is composition
• Atomic  indiscrete into smaller attribute
• Composition  constituting affiliate of some attribute which smaller

• Derived Attribute
• attribute that its point gets resultant of other attribute point, for example  resulting age of date attribute comes into the world
• Null Value Attribute
• Attribute that have no point for a record
• Mandatory Value Attribute
• Attribute who shall have point



RECORD / TUPLE
• Constitute a data row in a relationship
• Consisting of attribute bulk where that attribute interactions to inform entitas / comprehensive relationships


ENTITAS / IS FILE
• File constitutes bulk from record what do a sort and have same element, attribute is with but variably value's data.
• File type
In application proceedings, file that dikatagorikan can as follows:
– Parented file
– Transactions file
– Write-up file
– History file
– Protecting file
– Job file


DOMAIN
• Domain constitutes bulk of point that is let for lies deep one or more attribute. Each attribute in a relasional's data basis is defined as a domain
DATA ELEMENT KEY
• To y. is record's element that is used to find record that on access time or can also be utilized to identify each entity / record / the line.

TYPE GO TO Y.
• Superkey constitutes one or more attribute of a table applicabling to identify entityty / record of unique ala table (are not all attribute can be superkey)
• Cadidate Goes To y. be super goes to y. with minimal attribute. Candidate goes to y. may not contain attribute of the other table so candidate goes to y. definitely superkey but was obviously contrariwise.
• Primary Goes To y.
One of attribute from candidate goes to y. get to be chosen / is determined as primary goes to y. with three criterions as follows:
1. To y. that more natural to be utilized as basis
2. To y. that simpler
3. To y. that its uniqueness indemnity bond
• Alternate Goes To y. be attribute from candidate goes to y. that don't be chosen becomes primary to go to y..
• Foreign Goes To y. constitute bungling attribute which point for primary to go to y. on the other table. Foreign goes to y. will happen at one particular relationship which have kardinalitas one to many (one to there are many) or many to many (there are many to a lot of). Foreign goes to y. usually do ever be placed on table that aims to go to a lot of.
• External Goes To y. constitute a lexical attribute (or lexical's gathering attribute) one that its point do ever identify one object instance.
ERD (ENTITY RELATIONSHIP IS DIAGRAM)
• ERD is a model network which utilize wording that is kept in abstractive system.
• The difference among DFD and ERD
• DFD constitutes a logistic network model that will be performed by system
• ERD constitutes data network model that emphasizes on structure and relationship is data
ERD'S ELEMENTS
• ENTITY
On ER Entity's diagram is figured with square form long. Rntity is aught something in real system and also abstract where data is kept or where exists data.
• Relationship
On ER diagram relationship can be figured by one lozenged. Relationship is subjective artless one be become among entitas. In a general way given by name by says basic job so making easy to do its relationship perusal.
• Relationship Degree
are total entitas who participates in one relationship. Degree that frequent being used deep ERD.
• Attribute
are character or characteristic of every entitas and also relationship
• Kardinalitas
pointing out tupel's optimum that relations can with entities on entities another one


Degree relationship
• Unary Relationship
are model relationship that happening among entity what do come from same entity set.
• Binary Relationship
are model relationship that happening among 2 entities.
• ternary Relationship
constituting relationship among instance of 3 entities types unilateral.


KARDINALITAS
Available 3 cardinalities relationships which is
– One to One: Subjective zoom one to one stated with one instance on entities first, just has one relationship with one instance on entities secondly conversely.
– One to Many or 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.
– Many To Many: happening if each instance on one entities has many relationship with instance on another entities.
KARDINALITAS'S EXAMPLE




NOTATION (DIAGRAM E R)
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 Entities Gathering with its attribute