CHANGING DATA INTO INFORMATION AZRAI BIN KHIRRUDIN FAIRUZ AIMAN BIN RUMAZI NURUL DHAMIRAH ATHIRAH BINTI ABDUL AZIZ
Data • Consists of raw facts. • The facts have not yet been processed to reveal their meaning to the end user. • The foundation of information, which is the bedrock of knowledge. • Example: a list of names and phone no. that has not been categorised and tabulated.
Information • The result of processing raw data to reveal its meaning. • Information consists of transformed data and facilitates decision making. • Can be as simple as tabulating the data, thereby making certain data patterns more obvious.
Transformation • Any process that changes data into information. • Example: What the tree looks like is the data, but the photograph of the tree is information.
Summary • Data constitutes the building blocks of information. • Information is produced by processing data. • Information is used to reveal the meaning of data.
The Information System Anas Bahari Bin Mohamed Musli Fatin Nur Fariha Binti Abu Bakar Nur Rahima Binti Halim
The Information System A system that provides for data collection,storage and retrieval,facilitates the transformation of data into information. Manage both data and information. It composed hardware,DBSM and other software,database(s),people and procedures.
System Analysis Process that establishes the need for an information system and its extent. System Development Process of creating and information system.
Applications Transform data into information that forms basis for decision making Usually produce the following • Formal Report • Tabulations • Graphic displays Composed the following 2 parts • Data • Code: program instructions
Factors Of Performance • Database design and implementation • Application design and implementation • Administrative procedures Database Development Process of database design and implementation. Implementation phase: • Creating database storage structure • Loading data into the database • Providing for data management
AMIRUL HAIKAL BIN BADRUL MUNIRMOHAMMAD HABIBULLAH BIN ZAINOLSHAWALTUL NAJWA BT SAHAZALINUR HIDAYAH BT ABDUL RANI INTRODUCTION TO DATABASE SYSTEM MANAGEMENT (ITS 232) CHAPTER 6 6.3 : The Systems Development Life Cycle (SDLC)
Planning • General overview of the company and its objectives. • An initial assessment must be made during this discovery portion of the SDLC. • Assessment should answer some important question : • Should the existing system be replaced ? • Should the existing system be modified ? • Should the existing system be continued ? • The feasibility study must address the following : • The operational cost: Will they use or Do they need it ? • The system cost: Can we afford and will it benefits our company ? • The technical cost : Can we build and support it with our current technology ?
Analysis • Problems that are defined during the planning phase are examined thoroughly during the analysis phase. • A macro analysis must be made both for organizational needs and individual needs addressing question such as : • What are the requirements of the current system’s end user? • Do those requirements fit into the overall information requirements?
Detailed System Design • Designer completes the design of the system’s processes. • The design describe the software features in detail and generally include all necessary technical specifications such as : • Functional hierarchy diagrams • Screen layout diagrams • Tables of business rules • Business process diagrams • Other devices that might help make the system more efficient information generator
Implementation • Hardware, DBMS software, and application programs are installed • Database design is implemented • Cycle of coding, testing, and debugging continues until database is ready for delivery • Database is created and system is customized • Creation of tables and views • User authorizations
Maintenance • Three types of maintenance activity: • Corrective maintenance • Adaptive maintenance • Perfective maintenance • Computer-aided systems engineering (CASE) • Produce better systems within reasonable amount of time and at reasonable cost • CASE-produced applications are structured, documented, and standardized
DATABASE INITIAL STUDY • Overall purpose of the database study is to: • Analyze the company situation • Define problems and constraints • Define objectives • Define scope and boundaries • Interactive and iterative processes required to complete first phase of DBLC successfully
Analyze The Company Situation • The database designer must learn the company’s operational components, how they function and how they interact • The following issues must be resolved: What is the organization’s general operating environment and what is its mission within the environment? What is the organization’s structure?
Define Problems And Constraints • The designer need both formal and informal sources of information • The process of defining problems might initially appear to be unstructured • The designer is likely to collect very broad problem descriptions • Finding the precise answers is important especially concerning the operational relationships among business units • Sometimes even the most complete and accurate problem definition does not always lead to the perfect solution
Define Objectives • A proposed database system must be designed to help solve at least the major problems identified during the problem discovery process • The designer’s job is to make sure that his or her database design system objectives correspond to those envisioned by the end users • The database designer must begin to address the following questions: What is proposed system’s initial objective? Will system interface with other systems in the company? Will system share data with other systems or users?
Define Scope And Boundaries • The designer must recognize two sets of limit which are scope and boundaries • The system’s scope defines the extent of the design according to operational requirement • The proposed system is also subject to limits known as boundaries which are external to the system
Database design • Focus on design of database model that will support company operations and objectives. • Concentrate on the data characteristic required to build database model. • 2 views of data within system: • Business view - data as the source of information • Designer view - data structure, its access, and activities required to transform the data into information. • Database design are based on relational model.
Points to remember when examine the procedures requires in database design • The process is loosely related to the analysis and design of larger system. • The system analysts or system programmers are in charge of designing the other system components. • The database design does not constitute a sequential process, rather it is iterative process that provide continuous feedback.
Database design process • 3 essential stages: • Conceptual design overall data as seen by end-user • Logical design data seen by DBMS • Physical design data seen by the operating system’ storage management devices • Plus DBMS selection decision • More details about the data model are determined and documented at each stages.
IMPLEMENTATION AND LOADING • Actually implement all design specifications from previous phase: • Install the DBMS • Virtualization: creates logical representations of computing resources independent of physical resources • Create the Database • Load or Convert the Data
Install the DBMS • Required only when a new dedicated instance of the DBMS is necessary for the system. • DBMS may be installed on a new server or on existing servers. One current trend is called virtualization. • VIRTUALIZATION creates logical representations of computing resources independent of physical resources. used in many areas of computing,such as creation of virtual servers,virual storage and virtual private networks. • Another common trend the use of cloud database –Microsoft SQL Database Service.
Create the Database • Requires the creation of special storage-related constructs to set the end-user tables. • constructs include storage group/file groups table spaces tables • Storage group can contain more than one table space and that a table space can contain more than one table.
Load or convert the Data • After the database has been created, the data must be loaded into the database tables. • Data must be aggregated from multiple sources in a relational database. • In some cases, data can be imported from nonrelational databases, flat files, legacy systems or manual paper-and-pencil systems. • If data format does not support direct importing, the data may have to be manually. • Loading data into cloud-based database can be expensive because the price are based on the volume of data to be stored and the data that travels over the network.
TESTING AND EVALUATION • To ensure that it maintain the integrity and security of the data. • Data integrity is enforce by the DBMS through proper use of primary and foreign keys. • Many DBMS also support the creation of domain constraints and database triggers. • Testing will ensure that these constraints will properly designed and implemented. • Data stored in the company database must be protected from access by unauthorized users.
Test for the following : • Physical security allows only authorized personnel access to specific areas. • Password security allows the assignment of access rights to specific authorized users. • Access rights can be establish through the use of database software. • Audit trails are usually provided by the DBMS to check for access violations. • Data encryption can render data useless to unauthorized users who might have violated some of the database security layers. • Diskless workstations allow end users to access the database without being able to download the information from their workstations.
Fine tune the database • System that support rapid transaction will require the database to be implemented so that they provide superior performance during high volumes of inserts, updates and deletes. • Decision support system, may require superior performance for complex data retrieval task. • Many factors can affect the database’s performance on various tasks including the hardware and software environment in which the database exist. • The characteristics and the volumes of the data also affect database performance. • Important factors in database performance includes system and database configuration parameters such as data replacement, access path definition, the use of indexes, and the buffer size.
Evaluate the Database and Its application Programs • Testing and evaluation of the individual components should culminate in a variety of broader system tests to ensure that all of the components interact properly to meet the needs of the users Integration issues and deployment plants are refined user training is conducted System documentation is finalized
CONT’ • Backup and recovery plans are tested to ensure that the data contained in the database are protected against loss.Data backup and recovery procedures create a safety valve,ensuring the availability of consistent data.Database backup can be performed at many levels:- Full backup : All database objects are backed up in their entirety Differential backup : Objects that have been updated or modified since the last full backup are backed up Transaction log backup : Backs up only the transaction log operations • The database backup is stored in a secure place .The main purpose of the backup is to guarantee database restoration following a hardware or software
Operation • Once database has passed evaluation stage, it is considered operational. • Beginning of operational phase starts the process of system evolution • Problems could not have foreseen during testing phase begin to surface • Solutions may include : • Load-balancing software to distribute transactions among multiple computers • Increasing available cache for DBMS
Maintenance and Evolution • Require periodic maintenance : Preventive maintenance(back up) Corrective maintenance(recovery) Adaptive maintenance(enhance performance, add entity & attribute) • Assignment of access permissions and their maintenance for new and old users • Generation of database access statistics to improve efficiency and usefulness of system audits and to monitor system performance • Periodic security audits based on system-generated statistics
CHAPTER 6 DATABASE DESIGN STRATEGIES Group members: ABDUL MUHAIMIN BIN MUSTAFFA KAMAL NOR AZREEN BINTI RIZAL NUR ASYIKIN BINTI RAMLI
*Selection of primary emphasis on top-down or bottom-up procedures often depends on the scope of the problem or on personal preferences TOP-DOWN DESIGN BOTTOM-UP DESIGN TWO CLASSICAL APPROACHES
TOP-DOWN DESIGN • Identifying data sets • Defines data elements for each set • Involves identification of different entity types • Definition of each entity’s attributes • May be more easily to manage for situation in which the number, variety and complexity of entities, relations and transactions. • Example: ER model
BOTTOM-UP DESIGN • Defines attributes • Groups them to form entities • May be more productive for small database with few entities, attributes, relations and transactions. • Example: normalization process