Normalization

Database Design process
Gathering user / business's requirement. Develop e r Model bases user / business's requirements. Conversion e r Model goes to relationship gatherings (table). Normalization is relationship to remove anomaly. Implementation goes to database by make table for each relationship already most normalization.

Data Basis normalization

Normalization are process basis structure forming data so a considerable part ambiguity can be removed. Normalization phase is begun of lightest phase (1NF) until tightest (5NF) Just usually comes up 3NF's zoom or BCNF because was enough is equal to result qualified table good.
The importance for normalization:
- Since marks sense database structure that insufficiently lovely
- Saved same data at severally place (file or record)
- Disability to result particular information
- Information’s forfeit happening
- Happening marks sense redundancy (repeat) or data duplication so wastes storage room and wanting hard with while updating process data
- Mark sense NULL VALUE


Normalization step



Normalization process:

- Untied data in shaped table, hereafter analysis bases particular situating go to many zooms.
- If table examinee has qualified particular, therefore table that needs to be broken down becomes many table that simpler until optimal form pock.

To the effect Normalization:

- to remove duplicate data
- to reduce complexity
- to water down modification data

Why done by normalization?

- Optimal is table's structures
- Increasing speed
- Removing same data inclusion
- More efficient in storage media purpose
- Reducing redundancy
- Avoiding anomaly ( insertion anomalies , deletion anomalies , anomaly’s update ).
- Increased data integrity

One table is said well (efficient) or normal if pock 3 criterions as follows:
- If there is decomposition (decomposition) table, therefore decomposition it shall be secured safe( Lossless Join Decomposition ). Its mean, after that table is untied / at decomposition becomes new tables, that new tables can result tables originally equally a hair's breadth.
- Its petted dependable functional at the moment data change (Dependency Preservation).
- Don't breach Boyce Code Form's Normal (BCNF)


Functional Dependency

To do normalization, shall can determine earlier Functional Dependency (FD) or Functional dependency, notably deep do database design decomposition.
Functional Dependency (FD) can symbol with:
A -> B: its mean b have dependency with A
Matter a. functionally determine B or b functionally depend on A.


• Functional Dependency figuring relationship attributes in one relationship
• An attribute is said functionally dependant on the other if we utilize to assess that attribute to determine the other attribute point.
• Symbol that is utilized is -> for representing functional dependency.
-> read functionally determines
• Notation: A. -> B
A. and b is attribute of one table. Matter functionally a. determines b or b cling to, if and only if available 2 data row with appreciative a. same, therefore point b also with
• Notation: A. -> B or a. x -> B
Are opposite of previous notation.

• Example:




Functional Dependency:
• NRP -> Name
• Lesson, NRP -> Point
Non Functional Dependency:
• Lesson -> NRP
• NRP -> Point

• Functional Dependency of point table
– NRP -> Name
Since for each point same NRP, therefore Name point also with
– {Lesson, NRP} -> Point
Since attribute Assesses to cling to Lesson and NRP IS ala goes together. In other mean for Lesson and same NRP, therefore Point also with, since Lesson and NRP constitutes to go to y. (get unique character).
– Lesson -> NRP
– NRP -> Point


Normalization forms

While design database utilizes relational model, we often find severally alternative in definition relationship scheme gathering. Severally selection more comfortable disbanding option – other option for medley motive. Normalization order is declared for in normal shaped terminology. Normal form are a ruling one be put on on relationships in data basis and has to be accomplished by that relationship on normalization levels. A relationship is said in given normal form if given condition pocks.
Form – Normalization form whatever available in design data basis is that of
following:

a. FIRST NORMAL FORM (First is Form's Normal 1NF)

A relationship was said to form first normal, if and only if each monovalent attribute for each row. Every field just one savvy, not such word bulk that have mean two, just one mean just and also is not fraction say – word so its other mean.
Don't be permitted mark sense:
• Attribute that valuably there are many( Multivalued attribute ).
• Attribute composite or combine of both.
Example:
This following is data example on clerk relationship already accomplishes
first normal form.



This following is data example on college student relationship that haven't accomplished
first normal form.



College student relationship that have NIM, name and Sponsor Lecturer follows 3
college eye, that table haven't accomplished first normal because available repetitive
Code Lesson 3 times eventually that can be made 1 attribute just. So first normal form of data upon is:



SECOND NORMAL FORM (second is Form's Normal 2NF) (1 )

Both of Normal Shaped definition (2 NF) are:
1 ). Shaped pock 1 NF (first normal).
2 ). Attribute doesn't key to have logistic ala dependent on main key /
primary goes to y. .
So to form normal both of every table / must file is determined keys its attribute. Attribute key has unique and get to represent attribute any other that as its member. On College Student table example that accomplishes first normal (1 NF) , visually that NIM constitute Primary Goes To y. (PK). NIM -> Name, Guardian lecturer . Its mean is that Name attribute and Sponsor Lecturer hinges on NIM.
But NIM -> Lesson. Its mean is bahqa attribute Lesson not depends
on NIM.

For meeting normal both of, therefore on that college student table is broken down
as 2 tables as follows:








DRD NORMAL FORM (Third is Form's Normal 3NF)

Normal Shaped definition drd (3 NF) are:
1 ). Shaped pock 2 NF (second normal).
2 ). Attribute doesn't key have no dependensi transitiving to keys
main / primary goes to y..
Following Samples relationship that accomplishes to form 2 NF, but doesn't accomplish to form 3
NF.



Attribute No. Order and No. Massage constitutes prime key, well code item and name
item has dependensi functional to that prime key.
On table upon, each code item with, therefore item's name point also with,
so pointing out marks sense dependensi two that attribute, but which that
determine, what is item's code hinges on item's name, or contrariwise? So
item's name has dependensi functionaling to item's Code.
On this relationship points out that item's name have no dependensi ala
directly to prime key (No. order and No. Massage). In other words Name
Item has dependensi transitive to prime key.
So for meeting form 3 NF, therefore relationship upon at decomposition becomes
two relationships as follows:




Boyce Codd's form Form's Normal (BNCF)

BCNF'S Shaped definition is:
1 ). Shaped pock 3 NF (drd normal).
2 ). All conditioner (determinant) are key candidate (attribute that gets unique character).
Each attribute shall hinge function on super key's attribute.
BCNF constitutes to form normal as remedial as to 3 NF. A relationship
that BCNF'S pock always accomplishes 3 NF, but don't for on the contrary. A
relationship that accomplishes 3 NF was obviously accomplishes BCNF. Since form 3 NF
still enable anomali's happening.
On this following example exists seminar table, prime key is number student +
seminar, with that savvy:
_ Student can take a or two seminar.
_ Each seminar needs 2 instructors.
_ Each student led by either one 2 seminar instructors.
_ Each instructor just may take one seminar just.

On this example, number student and seminar points out an instructor.




Tabular seminar is accomplish forms DRD normal (3 NF), but don't
BCNF because seminar number is still hinge function on instructor, if each
instructor can teach at only one seminar. Logistic dependent seminar
on one attribute is not super key as one presupposed by BCNF.
Therefore seminar table shall at decomposition becomes two tables, which is instructor table
and seminar_instructor, as following as this:



Fourth normal form and to five
• Relationship in shaped fourth normal (4 NF) if relationship in BCNF and tdak contains dependency a lot of point. To remove dependency there are many point of one relationship, we divide relationship become two new relationships. Each relationship contains two attributes that have relationship a lot of points.
• Relationship in shaped normal to five (5NF) get business with property is join the so called without marks sense information loss (lossless join). Form normaling to five (5 NF also so-called PJNF (projection join is form's normal). This case very rare appearance and hard to be detected practical ala.

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

DATA FLOW CHART

DATA FLOW CHART

DFD constitutes system scheme tool that gets orientation on grooves data with decomposition concept can be utilized for delineation to analyses and also easy system design communicated by system professional to user and also program maker. Data flow chart called also Data flow diagram (DFD). DFD is model makings tool that enable system professional to figure system as a functional process network that linked each other with data path, well manually and also computerization. DFD this frequent so-called also by the name of Bubble Chart, Bubble is diagram, model processes, work flow diagram, or function model. DFD can make Easy user that insufficiently understand computer area for understands system who will be worked.

DFD'S makings steps :
1. Identification all outer unity that involved with system.
2. Input identification and output what do be engaged extern unity
3. Make picture of diagram context

DFD'S function:
1. DFD helps analysts sitem briefs informas about system, knowing relationship among system sub sub, fostering application effectively.
2. DFD functions as communication device that good among user and system analyst.
3. DFD can figure a number automation limitation for developmental alternative physical system.

CONTEXT DIAGRAM

Consisting of one process and figures scope of a system. Constituting supreme level from DFD what does figure all input goes to system and output of system. System drew the line by boundary (figured by dotted line). May not there is stored (storage). Context diagram in function map environment model (figuring relationship among
entities is extern, entry and system output), one that presentation with whorled
singles that represent system overall. DFD leveled figures system
as network of job among logistic one communicates mutually with flow
and laid up data, this model just model system of viewpoint
function
Context diagram is upstairs diagram, constituting diagram of one system which figure data flows in going and sticking out of system and ingoing and sticking out from entities extern. Thing Who shall be noticed:
1. Giving picture about exhaustive system
2. Terminal that give entry to source's so-called system
3. Terminal that accept sink's so-called output
4. There's only one process
5. May not there is data store



ZERO DIAGRAM

On this zero diagram what does amends just process and data path that link its process, meanwhile terminator's amount and incoming data path or outward from terminator, regular. Figuring process from DFD. give view thoroughly hit handled system, pointing out function or aught main process, data flow and eskternal entity. On this level is enabled marks sense storage's data. To process that don't elaborated again on succeeding level therefore enhanced symbol ‘ * ’ or ‘ p ’ at the early process numbers. Balance input and output (balancing) among diagram 0 by context diagram shall be petted
Thing that needs to be noticed:
1. Show store's data that is utilized
2. On process that don't elaborated again, add sign * at the early
process numbering
3. Balance among context diagram and zero diagram shall
Petted

DETAIL DIAGRAM

Detail diagram which is a diagram break even functional diagram and
each diagram linked by one systems logistic sub
One that has to be noticed:
1. Balance data flow among zero diagram and detail's diagram
2. On process that don't elaborated again, add sign * at the early numbering process
3. Balance data store who is utilized

Constituting diagram that describes to process what’s aught diagrammatically zero or level on it,
Numbering level on DFD:



In one advisable level has no is more than 7 processes and maximal 9, if more therefore has to be done by decomposition

SPECIFICATION PROCESSES

Each process on DFD shall have process specification. On top level methodic that is utilized to figure process can by use of descriptive sentence. On more level detail which is on lowermost process (functional primitive) needing more specification most structure.
Specification processes will be guidance divide programmer in makes program (coding). Method that is utilized in specification processes: breakdown of process in shaped story, decision table, decision tree.
OUTER UNITY

Beyond something system, but it gives data into system or gives data of system. At symbol with notation box. External entity excluding part of system.
Naming:
• Terminal name as substantive as
• Terminal may not have same name but object it really with


DATA CURRENT

Constituting place is adrift information. Figured by straight line that link component of system. Data current is pointed out with aim shoots and lining be given by name on current data which is adrift. Data current is adrift between process, storage's data and points out data current of data that as entry for system.

Name application guidance:
• Data’s streaming name which consisting of umpteen flow say to be linked by interlocking lining
• May not there is streaming data which its name with and name application shall reflect its content
• Data flow that consisting of umpteen element gets to be declared for by element group
• Avoid word purpose ‘ data ’ and ‘ information ’ to give name on streaming data
• As much as can data flow name is written fledged

Other rule:
• Data’s streaming name which turn in at a process may not same by the name of secretory data flow of that process
• flow's data ingoing goes to or issue of storage's data not necessarily been given name if:
• Simple data flow and perspicuous
• Data flow figures all item's data
• May not there is streaming data of terminal go to storage's data or on the contrary since terminal is not part of system, terminal relationship with data storage shall pass through process.

PROCESS

A process is an activity or work done by the person, machine or a computer from the data that flow into the process to produce data that will flow out of the process.

The process is what is done by the system. The process can process data flows or data entry into the flow of data out . Transform the process of working one or more of the input data into one or more of the output data in accordance with the desired specifications. Each process has one or more inputs and produce one or more output.
The process also often called bubble.

Guidelines of the process:
1. Name of the process consists of a verb and noun, which reflects the function of the process.
2. Do not use the process as part of the name of a bubble.
3. May not have some process that has the same name
4. The process should be given a number. Order number wherever possible to follow the flow of the process or sequence, but the sequence number does not mean that the absolute is a process in chronological order

DATA TROVE

Data storage is a storage place for data that exists in the system
at symbol with a pair of parallel lines or two lines with one side open side. The process can retrieve data from or provide data to the database
Guidelines of the name:
1. The name should reflect the data storage.
2. When his name more than one word must be marked with the number.

DFD SYMBOLS



DATA DICTIONARY

Systems or data dictionary data dictionary is a catalog of data on information needs and the needs of an information system. Have functions to help the system to interpret the application in detail and organize all elements of the data used in the system precisely so that the system analyst and have a basic understanding of the same input, output, storage and processing. At analysis, the data dictionary is used as a means of communication between the systems analyst with the user. At the system design, data dictionary is used to design input, reports and databases
DFD data flow on a global, more detailed information can be seen in the data dictionary.

Content Data Dictionary :

a. Name of the data flow.
b. Alias
c. Form of data.
d. Flow data.
e. Explanation. Description
f. Period. Period
g. Volume.
h. Data structure.

Load the data dictionary as follows:
1. Name of data flow: must note that readers who need further explanation about a flow of data can find it easily.
2. Alias: alias or other name of the data can be written if there is.
3. Forms of data: used to segment the data dictionary to use when designing the system.
4. Flow data: indicates from which data flows and where the data.
5. Description: to give an explanation of the meaning of the data flow

Balancing IN DFD

The flow of data into and out of a process must be the same as the flow of data into and out of the details of the process on the level / levels below it. Name of the data flow into and out of the process must match the name of the flow of data into and out of the details of the process. Number and the name of an entity outside the process must be equal to the number of names and entities outside of the details of the process. The issues that must be considered in the DFD which have more than one level:
1. There must be a balance between input and output of one level and the next level.
2. Balance between level 0 and level 1 at the input / output of stream data to or from the terminal on level 0, while the balance between level 1 and level 2 is seen on the input / output of stream data to / from the process concerned.
3. Name of the flow of data, data storage and terminals at each level must be the same if its object same.

Restrictions in DFD

In drawing / DFD design there are several things that should be avoided, so the DFD
shows that overall the system will be designed, these things is:

1. Flow data may not be from outside the entity directly to other outside entities without going through a process.
2. Flow data may not be from the savings directly to the data to outside entities without going through a process.
3. Flow data may not be saving the data directly from the savings and other data without going through a process.
4. Flow data from one process directly to the other without going through the process of saving data should / be avoided as much as possible.