NORMALIZATION

There is example ER Diagram that normalization will be done :



Based on the above ERD, we can do process Mapping as follows:

For the normalization process, the need to do is remove the recurrence occurred on the table. Once we do this before the table is already in the form of 1NF.

In the second normal form, table of pegawai increased to 2 table.

A relationship is said to satisfy the third normal form relations, when the relation meet the second normal form and he attributes that are not key is not transitive dependent on the key itself. Same as in the second normal form, the changes only on the table pegawai only.

Database Normalization

Database is usually the one part of an information system that consists of, among others, Data, DBMS software, computer Hardware, software and computer operating systems, application programs, programmers.

There are database design process :

1. Collection and analysis requirement user.
2. Develop the ER model based on requirement user
3. Convert ER Model to set the relation (table)
4. Normalization of relations, for the anomaly
5. To implement the database for each table to create relationships that have been in the normalization

Normalization process is the establishment of the database structure so that most of the ambiguity can be removed. Normalization stage, starting from the most mild (1NF) to most stringent (5NF). Normalization is usually only up to the level of 3NF or BCNF because already sufficient to generate the table-a table of good quality. The purpose why we do Normalization is to loss of data double, decrease complexity, and to simplify data modification process.

Normalization purposes : minimize the repetition of information , to reduce the complexity and easily identify entities or objects.

Why do normalization?

1. Optimization table structures
2. Increase the speed of process.
3. Eliminate income data the same
4. More efficient use of storage media
5. Reduce redundancy
6. Avoiding anomalies (insertion anomalies, deletion anomalies, update anomalies).
7. Improved integrity data

A table saying good (efficient) or normal if following there 3 criteria :

1. If there is decomposition (decomposition) table, then the decomposition will be guaranteed safe (Lossless-Join Decomposition). That is, after the table is described / in the decomposition into a new table-table, the table-table can generate a new table with the same exact.
2. Maintain the functional dependence on the change data (Dependency preservation).
3. No violate Boyce-Code Normal Form (BCNF)

If the three criteria (BCNF) can not be met, then at least the table does not violate the Normal Form of the third stage (3rd Normal Form / 3NF).

Functional dependency (FD) is a restriction that comes from the meaning of attributes and relationships between attributes. Functional Dependency attributes describe the relationship in a relationship. An attribute said functionally dependant on the other, if we use the value attribute to determine the value of the other attributes. Symbol that is used to represent è functional dependency. è read the functional set. FD from the fact that there is (obtained at the analysis system).

Notation: A è B. Means A and B are attributes of a table. A means of determining the functional B or B depends on A, if and only if there are 2 rows of data with the same value of A, then B is also the same value.

Normal form is a condition (using the FD and key) that determines whether a scheme relationships meet certain criteria. There are several normal forms based on a number of criteria:

1. Primary keys (1NF, 2NF, 3NF)
2. All Candidate Keys (2NF, 3NF, BCNF)
3. Multivalued dependencies (4NF)
4. Join dependencies (5NF)

FIRST NORMAL FORM (First Normal Form - 1NF)

A table on the form said to be normal if I did not reside in the unnormalized form of a table, where there is a kind of field multiplication and field that allows a null (empty) 1NF is not allowed on the:

1. Attribute values, many (Multivalued attributes).
2. Attribute a composite or a combination of both.
3. Nested relations.

So, price is the domain attribute must be atomic rates.

Advantage of the 1NF compared Unnormalized relation (UNRs) is a simplification in the form of representation and ease of use in developing a query language

Second NORMAL FORM (Second Normal Form - 2NF)

Normal form 2NF met in a table if it meets the form of 1NF, and all the attributes than the primary key, have a full Functional Dependency on primary key. A table does not meet 2NF said, if there are attributes that Functional Dependency are only partial (only depending on the part of the primary key). If there are attributes that have no dependence on the primary key, then the attributes must be moved or removed.

• Functional dependency X à Y if it is said of a remove attribute A from X means that Y is no longer dependent functional.
• Functional dependency X à Y if it is said partial delete an attribute A from X means that Y is functionally dependent.
• Relation scheme R in the form 2NF if every non-primary key attribute A Î R is functionally dependent on the full primary key R.

Third NORMAL FORM (Third Normal Form - 3NF)

Normal form 3NF fulfilled if the form meets 2NF, and if there are no non-primary key attribute that has a dependence on non-primary key attributes of the other (transitive dependencies).

Table following students eligible 2NF, 3NF, but does not meet

Because the table above there are still non-primary key attribute (ie, Kota and Provinsi), which has a dependence on non-primary key attributes of the other (ie KodePos), namely:

KodePos à {Kota, Provinsi}

So that the table in the decomposition needs to be:

• Mahasiswa (NIM, NamaMhs, Jalan, KodePos)

– KodePos (KodePos, Provinsi, Kota)

Boyce-Codd Normal Form (BNCF)

Boyce-Codd Normal Form constraint has a stronger form of the Normal third. To be BNCF, relations must be in the First Normal Form and forced each of the attributes depends on the function in the super key attributes.

In the example below there is a relationship seminar, is the Primary Key NPM + Seminar. Students may take one or two seminars. Each seminar requires 2 each of the students and led by one of the 2 seminar. Each leader can only take one seminar course. NPM and Seminar in this example and show a Pembimbing.

Seminar relations is a Third Normal Form, but not BCNF because Code Seminar is still dependent on the function Pembimbing, if any Pembimbing can only teach a seminar. Depending on the seminar is not a super key attributes such as required by BCNF. But relations Seminar should be parsed into two namely:

Normal form of the fourth and fifth

Relations in fourth normal form (NF 4) if the relation in BCNF and does not contain a lot of dependence values. To remove the dependency of many values from a relation, we divide the relationship into two new relations. Each relation contains two attributes that have a lot of relationship value.

Relations in fifth normal form (5NF) deal with the property called the join without any loss of information (lossless join). Fifth normal form also called the 5 NF PJNF (projection join normal form). The case is very rare and appear difficult to detect in practice.

Reference:

- http://iaprima.staff.gunadarma.ac.id/Downloads/files/5460/Bahasan9b_Normalisasi.pdf

- http://kuliah.dinus.ac.id/ika/prc4.html

- ER Ngurah Agus Sanjaya. Slide Part 6 - NORMALISASI.

DATABASE AND ER-DIAGRAM

DEFINITION OF DATABASE

- Database is group of data that stored into magnetic disk, optical disk, or other secondary data storage.

- Data base can also be defined as the collection of data, which can be described as the activities of one or more organizations that be relations. The database can be a collection of integrated data-related data of an enterprise (company, government or private).

- For example : manufacture company -> production planning data, actual production data, material ordering data, etc

DBMS (Database Management System)

- DBMS is software designed to assist in the maintenance and utility data collection in large numbers. DBMS can be the alternative specifically to the use of applications, such as data storage in field and write code for a specific application settings.

- The main purpose DBMS is to provide an environment that is efficient and easy to use, saving data and information.

- The main components DBMS can be divided into 4 types:

1. Hardware

2. Software

3. Data

4. User

BIT, BYTE, FIELD

- Bit is the smallest of data that contains value 0 and 1.

- Byte is collection of same bits.

- Field is collection of same bytes as known as attribute. Attribute is characteristics of an entity that provides a detailed explanation of these entities.

TYPES OF ATTRIBUTE

- 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, example : age can be yield from birth date attribute

- Null Value attribute is an attribute that has no value to a record.

- Mandatory Value attribute is a attribute that must have a value.

RECORD OR TUPPLE

- A data row inside a relation

- Consist of attribute collection which attribute interaction for advising entity or relation as detail

ENTITY OR FILE

- File is collection of record that have same kind and same element, which the same attribute, but different data value.

- Type of file, can be categorized as :

• Main file
• Transaction file
• Report file
• History file
• Protector file
• Work file

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

ELEMENT KEY OF DATA

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 or record.

TYPES OF KEY

- Superkey is one or more attribute that can be used for identification entity or record in table as uniquely (not all of attribute can be superkey).

- Candidate key is supperkey with minimal attribute. Candidate key cannot containing the attribute from other table, so candidate key already definite as superkey but not yet the other way.

- Primary key is one of candidate key that can be chosen or determined as primary key with 3 category, that is :

1. Key is more natural for used as reference

2. Key is more simple

3. Key is guaranteed the unique

- Alternate key is attribute from candidate key that not chosen as primary key

- Foreign key is any kind attribute that showing to primary key in other table. Foreign key happen in a relation that having cardinality one-to-many or many-to-one. Usually, Foreign key always put in table direct to many.

- External key is a lexical attribute (or compilation of lexical attribute) that its value always identification one object instance.

ERD ( ENTITY RELATIONSHIP DIAGRAM )

ERD is a model using word structure that saved in system as abstract. Difference between DFD and ERD :

o DFD is a function network model that will executed by system

o ERD is data network model that emphasize in structure and relationship data.

ELEMENTS OF THE ERD

1. Entity is something exist inside real system or abstract system which data stored or where are the data.

Symbolized as square of length. There are also line symbol as link between compilation of entity with entity and compilation entity with its attribute.

2. Relationship is natural relation happened between entity. Generally, given name with basic verb making it easier to reading it relations. Symbolized as rhomb.

3. Relationship Degree is the number of entities participating in a relationship.

4. Attribute is characteristic of each entity or relationship. Symbolized as circle

5. Cardinality show tupple maximum amount that can be relations with entities on the other entity.

RELATIONSHIP DEGREE

- Unary relationship is Relationship model happen between the entity which coming from the same entity set.

- Binary relationship is relationship model happen between 2 entity.

- Ternary relationship between instance of 3 entity unilaterally.

CARDINALITY
There are 3 cardinality relations, namely

1. 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

2. 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 view. For an incident on the first entity can have any relationship with many incident on the second entity, if the one incident on the second entity can only have one relation with the incident on the first entity.

3. Many To Many: if any incident occurs in many entity have relationships with other entities in the incident.

NOTATION (E-R DIAGRAM)

1. Rectangle represent the collective entity

2. Circle represent the attributes

3. Rhomb represent collective relationships

4. Line as the set of relationships between the entity and the collective entity with the attribute

REFERENCES :

- ER Ngurah Agus Sanjaya. Presentation Slide Part 5 - DATABASE DAN ER-DIAGRAM.
- Fathansyah, Basis Data, Informatika Bandung, Bandung, 2002

DATA FLOW DIAGRAM

DATA FLOW DIAGRAM

- Data Flow Diagram (DFD) is a graphic illustration of the system that uses a number of forms of symbols to describe how data flows through a process of inter-related. Despite the name this diagram emphasizes the data, the situation is vice versa: the emphasis is on the process.

- Some symbols used in the DFD to represent:

1. External entity

2. Data Flow

3. Process

4. Data Storage

CONTEXT DIAGRAM

- The diagram which consists of a process and describe the scope of a system.

- It is the highest level of the DFD that describes the entire system to input and output of the system

- The system is limited by Boundary (depicted by broken lines)

- No storage

ZERO DIAGRAM

- Diagram illustrating the process of the DFD. Giving views on the overall system in which, showing the main function or process that is, the flow of data and external entity.

- At this level of data storage is possible.

- To process the detailed no longer on the next level then added the symbol '*' or 'P' at the end of the process.

- Input and output balance (balancing) between 0 to diagram context diagram should be maintained.

DETAIL DIAGRAM

- Is a diagram of the process of decipher what is in the zero diagram level or above.

- Numbering of level at DFD:

Level Name	Diagram Name	Number of Process
0	Context
1	Diagram 0	1.0, 2.0, 3.0, ...
2	Diagram 1.0	1.1, 1.2, 1.3, ...
3	Diagram 1.1	1.1.1, 1.1.2, ...

- In the one level there should be no more than 7 units and the maximum of 9, when more should be done in the decomposition.

SPECIFICATION PROCESS

- Each process in the DFD must have a specification process.

- At the top level method is used to describe the process you can use with descriptive sentences.

- At a more detailed level, namely on the bottom (functional primitive) require a more structured specification.

- Specification process will be the guideline for the programmer to make this program (coding).

- Method used in the specification process: the process of disintegration in the form of a story, decision table, decision tree.

EXTERNAL ENTITY

- Something that is outside the system that will provide data to the system or providing data from the system.

- Symbol with the notation.

- Unity does not include the outside of the system

DATA FLOW

- Flow data consist of a group of related data elements in a logical move from one process to another process.

- Depicted with a straight line connecting the components of the system.

- Flow data is shown with the direction arrows and the name on the flow of data that flows.

- Cash flow of data between processes, saving data, the unit outside, and shows data flow from data in the form of inputs to the system.

- Guidelines of the name:

1. Name of the flow of data that consists of some words associated with the flow lines connect.

2. No flow data for the same and the name should reflect its content

3. The flow of data that consists of several elements can be expressed with the group element

4. Avoid using the word 'data' and 'information' to give a name to the flow of data

5. Wherever possible the complete flow of data is written

6. Name of the flow of data into a process may not be the same as the name of the data flow out of the process

7. Data flow into or out of data storage does not need to be given a name if:
- Flow of data simple and easy to understand
- Flow of data describes all data items

8. There can be no flow of data from the terminal to the data storage, or vice versa because the terminal is not part of the system, the relationship with the terminal data storage must be through the process.

PROCESS

- The process is to change the input into output. The process can symbolize with a circle or tetragon with this degree obtuse angles.

- The transform function of one or more of data input 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 several outputs.

- Each process must be given a full explanation include:

1. Identification process, namely the form of a figure that shows the reference number of the process and is written at the top.

2. Name of the process, that is what the show is done by the process.

3. Processing

DATA STORAGE

- Storage of data is the data that have savings in the system.

- Savings symbolize data with a pair of parallel lines or two lines with one of the side open.

- 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

DATA DICTIONARY

- Working 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 design stage of the system, the data dictionary is used to design input, reports and databases

- Flow data on the global DAD, further details can be seen in the data dictionary

- 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 support.

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

- 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 or levels below

- The flow of data 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 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 next level

2. Balance between level 0 and level 1 at the input or 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 or output of stream data to or from the process concerned

3. Name of the flow of data, data storage and terminals at each level must be the same if the same with this object.

RESTRICTIONS IN DFD

- Data flow may not be from outside the entity directly to other outside entities without going through a process.

- Data flow may not be from the savings directly to the data to outside entities without going through a process

- Data flow may not be saving the data directly from the savings and other data without going through a process.

- Data flow from one process directly to the other without going through the process of saving data or should be avoided as much as possible.

REFERENCE:

- Slide Kuliah : Diagram Aliran Data. NGURAH AGUS SANJAYA ER, S.KOM, M.KOM

- McLeod, Raymond. Sistem Informasi Manajemen Jilid 1

FIRST OBSERVATION AND ANALYSIS REQUIREMENT

CONCEPT OF INVESTIGATION SYSTEM
- Difference between purpose of system and the condition of system be in fact
- Detect the problems not real account :

1. Main too ideal
2. Less the source of power and or attitude
3. Measuring of system less accurate
4. Among of ideal system and in the meantime system
   

-Problem solving:

1. Spelling out of this system
2. Develop some alternative
3. Selection the best alternative
   

- Main of investigation is showing the problems be in fact.

CONSTRAINT IN INVESTIGATION SYSTEM
-Time
-Cost
-Knowledge
-Political

RECOMMENDATION
-Result from investigation are recommendation have content :

1. Not do action whatever it.
2. Maintenance of systems
3. Modification system totality
   

STRATEGY OF INVESTIGATION
-Find all problems
-Knows reason occurs problems
-Selection best solution
-Earing opinion of subject systems
-Don't do resolve early

TECHNIQUE OF INVESTIGATION
Direct :

1. Questionnaire
2. Dialogs
3. Research
   

Indirect :

1. Procedural flow
2. Study document
3. Sampel
   

REQUIREMENT ANALYSIS
-Requirement analysis is phase interaction between analyst system and end user, which develop team system showing skill for finding response and confidence user so get good partition
-4 Reach goal:

1. Description system complete
2. Description ideal information systems
3. Bring the ideal information system at moment with observe the resource constraint
4. Provide encouragement to the confidence in the develop system
   

-Document requirement analysis:

1. Direct analysis is relationship with end user, research process, problems of collecting data.
2. Requirement user is truth requirement.
3. Constraint systemsis description constraint time and cost, skill, technology and external factors.
   

GENERATING SYSTEM ALTERNATIVES
-Creating alternatives for resolve problems information systems
-Choice of strategy:

1. Distributed versus centralized processing
2. Integrated versus dispersed database
3. Surround strategy of system development
   

SELECTING THE PROPER SYSTEM
-Strategy to compare is system compared with be based on cost and relative advantage.
-Some method compare system:

1. Break Even point Analyisis
2. Payback Period
3. Discounted PayBack period
4. Internal Rate of Return
   

FACTOR INFORMATION SYSTEM
-Kualitative factors :

1. To decrease False
2. To decrease time for repaire false
3. To decrease respons time from workstation alternative
4. Increase safety systems
5. To desrease update source active record
6. Increase comfortable user
   

REPRESENTATION LEARNING SYSTEM
- Shortly presentation
- To decrease technically details
- Represented clearly with visual tools
- If use model, use tools like laptop so more informative
- Pushed profit from information system proposal with several alternative agree with company condition