A table on the form said to be normal 1 if 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). Relations, there is a condition in First Normal Form (1NF) if and only if all domains are covered only atomic value, for example, there is no recurrence group (domains) in a tuple. Advantage of the 1NF relation compared Unnormalized (UNRs) is a simplification in the form of representation and ease of use in developing a query language. Its Insuffiency is the need to duplicate data. Most of the system relations (not all) require a form of relations in 1NF.
2NF
The form of normal 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, if there are attributes that depended (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
3NF
3NF the changes only at the Pegawai table, Because there is no relation with the primary key that has a non-key attributes of each table above and all tables are considered normal up to 3NF.
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 Base Normalization
·Normalization is data base structure formation process so that a large part of ambiguity can be caused.
·Normalization step is begun from lightest step (1nf) up to tightest (5nf)
·Usually only until 3nf level or bcnf because that is enough proper to produce tables that have a good quality.
·A table is said good (efficient) or normal if fulfil 3 criterias as follows:
oIf there table decomposition, so decomposition must be guaranteed safe (lossless-join decomposition). That's mean, after table elaborated / decomposited be the new tables,the new tables can produce the first table with same exactly.
oFunctional dependence when data change (dependency preservation) was kept.
oDoesn't break Boyce-Code Normal Form (BCNF)
·If third criteria (BCNF) can not be fulfilled, so at least that table doesn't break normal form third stage (3rd normal form / 3nf).
Functional Dependency
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 used is (→) to deputize the functional dependency
·Notation: A → B
“A” And “ B” is attribute from a tables. Mean functionally A determine the B or B of depend on A, if and only if there is 2 data line with the same value A, hence assess the B also is of equal
·Notation: A /→ B Or A x→ B
Is reverse from previous notation.
Functional Dependency (FD)
·NRP -> Name
·Mata Kuliah, NRP-> Value
Non Functional Dependency:
·Mata Kuliah -> NRP
·NRP -> Value
Functional Dependency from tables of value
·Nrp -> Name Because for each value Nrp the same, then the value of the same name
·(Mata_kuliah, NRP) -> Value Because the value of attributes depending on the NRP and Mata_kuliah together. In another sense Mata_kuliah for the NRP and the same, they also rated the same, because Mata_kuliah and the NRP is a key (is unique).
·Mata_kuliah -> NRP
·NRP -> Value
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) not allowed:
Attribute values, many (Multivalued attributes).
Attribute a composite or a combination of both.
So:
Price is the domain attribute must be atomic rates
Example:
Ex Student Data as follows:
Ex Student Data as follows:
Second Normal Form - 2NF
Normal form 2NF fullfiled in a tables of if have fulfilled the form 1NF, and all attribute of besides primary key, intactly own the Functional Dependency of at primary key. A tables do not fulfill 2NF, if there is attribute which its depending only have the character of the just just parsial ( only depend on some of primary key) . If there are attribute which do not own the depending to primary key, hence the attribute have to be moved or eliminated.
-Functional depending of X → Y told by full of if vanishing a attribute A from X mean the Y shall no longger hinge functional.
-Functional depending of X →Y told by partial of if vanishing a attribute A from X mean the Y still hinge functional.
-Scheme of Relationship R in the form of 2NF if each every attribute of is non primary key A € R hinge full of by fungsional at primary key R.
-Tables in the following is fulfilling 1NF, but [do] not the inclusive of 2NF :
{NIM, KodeMk} → NameMhs
{NIM, KodeMk} → Address
{NIM, KodeMk} → Matakuliah
{NIM, KodeMk} → Sks
{NIM, KodeMk} → LetterValue
-The tables require to decomposition become some up to standard tables 2NF
· Functional dependency:
{NIM, KodeMk} → LetterValue (fd1)
NIM → {NameMhs, Address} (fd2)
KodeMk → {Matakuliah, Sks} (fd3)
· becoming :
fd1 (NIM, KodeMk, LetterValue) → Tables Value
fd2 (NIM, NameMhs, Address) → Tables of student
fd3 (KodeMk, Matakuliah, Sks) → Tables MataKuliah
Third Normal Form - 3NF
Normal form 3NF fullfiled by if have fulfilled the form 2NF, and otherwise there is attribute of is non primary key owning depending to attribute of is non primary key the other ( depending transitif)
· So that the tables require to didekomposisi become.:
· Student (NIM, NameMhs, Jalan, KodePos)
KodePos (KodePos, Provinsi, Town)
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 form of Normal To one 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 in this example and show the seminar.
Relations Seminar is a form of Third Normal, but not BCNF. Seminar Code because the function depends on the teach, if any teach can only teach a seminar. Depending on the seminar isn’t a super key attributes such as required by BCNF. So seminar relations must be parsed into two namely:
Normal Form Fourth And Fifth
Relation in the form of normal fourth (4NF) if relation in BCNF and not full multivalue dependence . To cause the loss of multivalue dependence from one relation, we divide relation be two new relations. Each full relation has two attributes that has multivalue connection.
Relation in the form of normal fifth (5NF) deal with property that called join without existence loses information (lossless join). Normal form fifth (5NF also called PJNF (Projection Join Normal Form). This case is very rare appears and difficult to detected according to practise.
References:
Er Ngurah Agus Sanjaya. Slide Part 6 - Normalisasi.
§The database is a set of data stored in the magnetic disk, optical disk or other secondary storage.
§Collection of integrated data-related data of an enterprise (company, government instance or private).
Company a manufacturing : production planning data, actual production data, data ordering materials, etc.
Hospital : patient data, doctor, nurse, etc.
DBMS
§System that is specifically created to make it easier to manage users in the database. The main purpose DBMS is to provide an environment that is efficient and easy to use, withdrawal and storage of data and information.
§The main purpose DBMS is to provide an environment that is efficient and easy to use, withdrawal and storage of data and information
Bit, Byte, Field
§Bit : Data bit is the part that contains the smallest value of 0 or 1.
§Byte : Byte is a set of bit-bit similar
§Field : Field is a set of byte-byte similar, in the database used the term attribute
ATTRIBUTE
It is the nature or characteristics of an entity that provides provide detail on these entities
A relationship can also have attributes
Example attributes:
STUDENTS: NIM, NAME, ADDRESS
CAR: NOMOR PLAT, COLOR, TYPE, CC
ATTRIBUTE TYPE
§Single Vs Multivalue Single: can only be filled at most one value
Multivalue: can be filled with more than one value with the same type of
§Atomic Vs Composition Atomic: can not be divided into the attributes of smaller
Composition: is a combination of several attributes of a smaller
§Derived attribute Attributes are derived attribute whose value can be derived from the value of other attributes, age attributes resulting from the date of birth
§Null Value attribute Attributes that have no value to a record
§Mandatory attribute Value Attribute should have a value
RECORD/TUPLE
§Record is a row of data in a relationship. Consists of the set of attributes where the attribute-attribute-attribute is to inform each other entity / relationship fully
ENTITY
§File is a collection of similar records and have the same elements, the same attributes but different data value.
§In processing applications, files can categorized 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 relasional is defined as a domain
DATA ELEMENT KEY
§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.
KEY TYPES
Superkey is one or more attributes of a table that can be used to identify entityty / record of the table are unique (not all attributes can be superkey)
Candidate Key is a super key with minimal attributes. Candidate must not contain a key attribute of the table so that the other candidate key is certain superkey but not necessarily vice versa.
Primary Key is one of the key attributes of the candidate can be selected / specified a primary key
Alternate Key is an attribute of the candidate key is not selected to be primary key.
Foreign Key is any attribute that points to the primary key in another table. Foreign key will be going on a relationship that has kardinalitas one to many (one to many) or many to many (many to many). Foreign key is usually always put on the table that point to many.
External Key is a lexical attribute (or set of lexical attributes) that values are always identify an object instance.
ERD
§ERD is a model of a network that uses word order is stored in the abstract system.
§Differences between the DFD and ERD :
DFD is a model of network functions that will be implemented by the system.
ERD is a model that emphasizes the network data on the structure and relationshipdata.
ERDELEMENT
§Entity In the ER Diagram Entity is describe with the form of a rectangle. Entity is something that exists in the real system and the abstract where the data stored or where there are data.
§Relationship ER diagram on the relationship can be described with a lozenge. Relationship is a natural relationship that occurs between entities. In general, the name given to the verb base making it easier to do read the relation.
§Relationship Degree is the number of entities participating in a relationship. Degree which is often use in the ERD.
§Attribute Attribute is the nature or characteristics of each entity and relationship.
§Kardinalitas Tupel indicates the maximum number that can be relation with entities on the other entity.
RELATIONSHIP DEGREE
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.
KARDINALITAS
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.
EXAMPLES KARDINALITAS
NOTATION (ERD)
§Symbolic notation in the ER diagram is : 1. Rectangle represent the collective entity
2. Circle represent the attributes
3. Rhomb express collective relationships
4. Line as the set of relationships between the collective relation whit the collective entity and collective entity with attribute.
(ENTITY COLLECTIVE, ATTRIBUTE A AS KEY, RELATION COLLECTIVE, AND LINK)
Depicting the division of system into smaller module Facilitating less comprehending user of computer area to understand system to be done.
DIAGRAM CONTEXT Consist of one process and depict scope from a system Representing highest level of DFD depicting all input to the system and output of system System limited by boundary (depicted by dash line) There may not be any is depository ( storage)
ZERO DIAGRAM Depicting process of DFD Opening on by totally regarding system handled, showing existing especial process or function, data stream and external entity At this level there enabled by the existence of data storage For process which not detailed again at level hereinafter hence enhanced by symbol ‘*’ or ‘ P’ by the end of process number Input balance and output ( balancing) among diagram 0 with context diagram have to be looked after
DETAILED DIAGRAM Representing diagram elaborating process there is in zero diagram or level above him Level Numbering at DFD :
In one level shall not there are more than 7 process and maximal 9, if/when more hence must be done composition3
SPECIFICATION OF PROCESS Every process at DFD have the specification of process method level top used to depict process earn using by descriptive sentence more level detailed that is process most under ( functional primitive) requiring more of structure specification Specification of process will become guidance to programmer in making program ( coding) Method which used in specification of process : breakdown of process in the form of story, decision table , decision tree
EXTERNAL UNITY Something that beyond system, but it's given data into system or give data of system Symbol with notation box External entity do not including the part of system. Naming : ● Name of terminal in the form of noun ● Terminal may not have the name of [is] same except its [is] same object (it) is true
CURRENT DATA Representing place a stream of information Depicted with connective straight line component of system Data current shown with direction bow and line called a stream of data current Data current stream among of process, data storage and show data current of data which in the form of input for the system
Guidance gift of name : ● Name of data stream which consist of some word stream attributed to continued line ● There may not be any data stream which its same name and gift of name have to express its contents ● Data stream which consist of some element can be expressed with element group ● Avoid usage of word ‘ data’ and ‘ information’ to give the name at data stream ● As possible the name of data stream written is complete.
Other rule: Name of data stream which entered into a process may not equal with the name of secretory of process data stream Data Flow which entered or go out from data storage needn't be called if : ● simple data stream and easy to comprehended ● Data stream depict all data item There may be not any data stream from terminal to data storage or on the contrary because terminal non part of system, relation of terminal with data storage have to through process
Process Process represent what done by system Process can process data stream or data enter to become exit data stream Functioning of process to transformation one or some input data become one or some output data as according to specification which wanted Every process have one or some input and also yield one or some output Process often is also referred by bubble Guidance of gift of process name: ● Name of process consist of noun and vb. expressing process function ● Don't use word process as part of the name of bubble ● There may not be any some process owning the name is same ● Process must have number. Number sequence as possible follow process sequence or stream, but that way meaningless number sequence absolutely represent sequence process chronologically
DEPOSIT DATA Data Storage represent existing data repository in system Symbol with a couple of parallel line or two line wrongly one side from other side openly Process can take data from or give data to database Guidance to gift of name: ● Name have to express data of storage ● If its name more than one word hence have to say the word to joint.
DICTIONARY DATA Functioning assist perpetrator of system to interpret application in detail and organizational all used by data element system precisely so that user and system analyst have same congeniality base about input, output, depository and process At analysis phase, data dictionary used by communication means among of system analyst with user At phase scheme of system, data dictionary used to design input, database and report Data current at DAD have the character of globally, more detailed can be seen at data dictionary Data dictionary load the followings : ● Name of data current : have to be noted so that reader which needing furthermore clarification about a data current can look for it easily ● Alias : alias or the other name can be written ● Data form: used to group data dictionary into its use time scheme of system ● Data current: showing where from data emit a stream of and where destination of data ● Clarification: giving clarification about meaning of data current
BALANCING IN DFD Stream Data which entered and go out from one process have to same with data stream which entered and go out from detail process of level / level below Name of data stream which entered and go out from one process have to same with name of data stream which enter into and go out from detail of process Amount and name of external entity from a process have to same with name and amount of external entity from detail of process. Things which must be gave attention to DFD owning more than one level: Have to there are input balance and of output among one and next level Balance among level 0 and level 1 seen at input / output of data stream or from terminal at level 0, while balance among level 1 and level 2 seen at input / output of data stream from pertinent process Name of data stream, data storage and terminal every level have to be same if its same object
PROHIBITION ORDER IN DFD Data current may not from direct external entity go to other external entity without passing a process Data current may not from direct data deposit go to external entity without passing a process Data current may not from direct data deposit go to the other data deposit without passing a process Data current from one direct process go to the other process without passing a data deposit can be possible avoided
Development of the system may mean preparing a new system for replace
The old system or improve the overall system existing.
Need for Development of System:
• There is a problem (problem) that arise in the old system
The problems that arise can be:
·Irregularity
·Organizational growth
• To seize the opportunity (opportunities)
Information technology has developed so quickly
• The instructions (directives)
2 Destination development system
Development means the system can arrange a new system to replace the old system as a whole or improve the existing system. The old system need to be replaced or repaired is because some things are as follows:
• The existence of the problems that arise in the old system. The problems that arise can be:
a. Irregularity
Irregularity in the old system caused the old system can’t operate in accordance with that expected. This irregularity may be operating inefficiently.
b. The growth of the organization
Growth of the organization must be the establishment of a new system. The growth of these organizations is the information needs of the area, the volume of data increases, changes in the new accounting principles.
• To capture the opportunities
Organization began to feel that information technology should be used to improve the provision of information so that it can support in the decision making process that will be done by management. Competitive in the market, the efficiency or speed of information that is not to determine the success or strategy plan and that plan has been developed to seize the opportunities that exist. If competitors can utilize, while the company can not take advantage of this technology, the opportunity will fall caption competition.
• The instructions
Preparation of the new system can also occur because of instructions from the top leadership or from outside organizations, such as government regulations.
3. Expected on the new system
Has been developed with the new system, the expected increase will occur, the increase in the new system.
• Performance
Improvement of the performance of the new system which will be most effective. Performance can be measured from the throughput and response time.
• Information
Improving the quality of information presented.
• Economy
Improvement of the benefits or the benefits or a decrease in the cost-reduction.
• Control
Detect and fix errors that occur and will occur.
• Efficiency
Improvement of operational efficiency.
• Services
Improvement of the services provided by the system.
4. SYSTEM DEVELOPMENT PRINCIPLES
• The system is developed for management
• The system developed is a large capital investment
Investment capital should consider 2 things:
1. 1. All alternatives should be investigated
2. 2. Investment should be the best value
• System developed need educated people who
Stages of work and tasks that must be made in the development process system
• The development of the system does not have to order
• Do not be afraid to cancel the project
• Documentation must be available to guide in the development of the system
5. System development life cycle
Waterfall Model
Contains a series of activities such as the process has been described above and presented in a separate process, such as the requirement specification, design implementation software, testing . After each step is defined, this step in the sign off and followed the development in the next step.
The steps that are important in this model is
The analysis and specification
Services, goals and constraints resulting from consultation with users system. Then everything is made in the form that can be understood by users and staff developers.
Design systems and software
Divide the system design process needs to be system software or hardware. The process produces an overall system architecture. Design software, including the functions of system software that may be in the form of the transformation in one or more programs that can be run.
Implementation and unit testing
During this stage, the design software we realize as a complete program or program unit. Test units, including units that each test according to specification.
Integration and system testing
Unit tested and integrated into the system that the program can complete requirements for the software has been met. After testing, the system was delivered to the customer
Operation and maintenance
This phase is long. System installed and used. Maintenance, including correction of errors not found in the previous step. Improvements to the implementation of the system and increasing service needs of the new system as found.
Iterative Model
Step-step model Iterative
1. Initial planning
Starting from the initial planning.
2. Planning
this stage, the stages where the plan is structured in such a way to get a system that both the good and the output
3. Requirements
Analyze user needs and the needs of the system
4. Analysis and design
in this process is conducted to analyze the process of the system will be developed and began to design the system.
5. Implementation
In this process is the system that has been created.
6. Testing at this stage, the system will try to test, to see if in conformity with the desire.
7. Evaluation this phase will be done from the system evaluation have been made.
Spiral model
Spiral model describes the process as a spiral which is divided into 4 quadrants:
process in accordance with the cycle using the prototyping approach.
• Planning namely the duties to plan, gather for the alternative system that will have • Risk Analysis
is to evaluate the alternatives based on the objectives and constraints. Included here to identify the certainty and risk
• Engineering
that is a task that is required to build one or more statements of this section
• Customer Evaluation.
Re-evaluate the system that was created with the customer
System development approach
• A structured approach versus classical approach (seen from the methodology used)
• Piecemeal approachversus system approach (seen from the target to be achieved)
• The bottom-up approach versus top-down approach (seen from how to determine the needs of the system)
• Total-system approach versus modular approach(seen from the way the developing)
• Great loop- approach versus evolutionary approach approach(seen from the technology that will be used)
A structured approach versus classical opponent approach
Classical approach
• Stages in SDLC-stage
• not to include users, system analysts put more emphasis
• The problem: the development of hard, expensive treatment, the possibility of error, success is less assured, the problems in the implementation of
Structured approach
• User involvement from the beginning to determine the needs of the system
• Using tools-tools such as data flow diagrams
Piecemeal approach versus system approach
Piecemeal approach
• Emphasizing on an application or event
• don’t override the overall target
System approach
• Viewing the system as a whole is unity
• Emphasizing the achievement of overall objectives
Bottom-up approach versus top-down approach
Bottom-up approach
• Starting from the bottom level of the operational
• It is the characteristics of classical
• Known by the term data-analysis
Top-down approach
• Starting from the top-level strategy planning
• It is the characteristics of structured
• Also known to the decision-analysis
Total-system approach versus modular approach
Total-system approach
• Develop a system simultaneously and comprehensively
• It is the characteristics of classical approach
Modular approach
• break a complex system into parts of a simple
• System to be developed on time, easy to understand and kept
• It is the characteristics of structured
Great loop- approach versus evolutionary approach approach
great-loop approach approach
• Develop a system simultaneously using the advanced technology
• At risk and spend a lot of high cost
evolutionary approach approach
• Applying advanced technology for application-specific applications
• Developed for the needs
• Save the cost and can follow the development of technology
7. Methodology, method and algorithm
• Methodology
Is methods used in science
• Method
A systematic way to grind
• Algorithm
Sort-order the procedure to solve a problem
8. Classification of development methodology
• Functional decomposition
– Emphasizing the breakthrough system subsystem
– Example: HIPO, Stepwise refinement, iterative stepwise refinement, information hiding
• Data-oriented
– Emphasizing on the characteristics of the data processed
• Data-flow oriented: modules according to the type of data elements
• Data-structure oriented: structure of the input and output
• Prescriptive
– Usually provided by the manufacturer of the software
9. Tool for developing a system
1. Graphics
- HIPO, DFD, SADT, W/O, JSD
2. Design
a. Chart for drawing activities
b. Chart for position arrangement
c. Chart for drawing personal relationship
10. Techniques used for the development of the system include:
Systems analyst is a person who analyzes the system with learning
problems that arise and determine the needs of users and
identify solutions that reasonless (better understand the aspects
business and computer technology).
Programmer who is writing code for an application program
based on a design made by the system analysts (better understand
computer technology).
After charting the information in the want ads, the results show that excellent verbal and written communication skills are a must for anyone wishing to pursue a career as a systems analyst. He or she also needs to be able to cooperate and get along with others while thriving in a team-oriented environment. A systems analyst needs to analyze and solve problems in an efficient manner so as to achieve results and meet deadlines. He or she should be able to mentally handle having several projects to monitor simultaneously, while possessing the ability to organize, prioritize, and show initiative in attacking the problem at hand. Technical expertise and attention to detail are also critical.
