The definition of database or also known as database in English is a collection of information stored in electronic media or computers in a systematic manner. The data is also processed in such a way so that it can be used easily. Usually, the term database or database is studied in information science. Initially, databases existed in computer science and then extended to the field of electronics. In addition, the notion of database in simple terms can also be interpreted as a collection of data that is interconnected with one another and has various uses.
Data base also means a collection of data that is mechanical, defined, and formally divided through an organization. Data base is operational data that is used by the system from the application of organization. Database is also defined as an integrated file system and has at least one primary key for a loop.
Database processing in computer media is intended to simplify and of course follow the times that increasingly implement the computerized era. A database management system in the IT world is commonly known as a DBMS (Database Management System). A database can also be defined consisting of a collection of tables that store data and information.
However, in essence the application of databases is not only in the IT scope, but is more than that. For example, in schools or universities, there is a database of students, students, teaching staff, infrastructure and others. In a company environment, of course there are company data including employee, financial, and other databases.
Database Concepts and Database Systems
Database is a collection of connected data that is stored together on a medium, organized according to a certain scheme or structure, and with software to perform manipulations for certain uses.
From this understanding, it can be concluded that the database has several important criteria, namely:
– Data oriented and not program oriented.
– Can be used by several application programs without the need to change the database.
– Can expand easily, both in volume and structure.
– Can meet the needs of new systems easily.
– Can be used in different ways.
From some of these criteria, it appears that there is a significant difference between data-based files and conventional files that are more program-oriented, that is, it can only be used by one application program, it only deals with a certain problem for the planned system, data development is only possible. on data volume only, data duplication is not controlled.
Database utilization:
– As one of the important components in an information system, because it is the basis for providing information
– Determine the quality of information: accurate, timely and relevant.
– Reduce data duplication (data redundancy)
– Data relationship can be improved
– Manipulation of data quickly and easily
– Efficient use of storage space
Furthermore, the database system is a set of databases with users who use the database together. Individuals who design and manage databases and computer systems to support them.
Thus the database system has several important elements, namely the database as the core of the database system, software for managing the database, hardware as a support for data processing operations, and humans who have an important role in the system.
There are several things that must be adhered to in database files in order to meet the criteria as a database, namely matters related to data redundancy, data inconsistencies, isolated data, data security and data integrity. In detail, this is described as follows:
- Data redundancy, which is the storage of the same data item from more than one physical location. Generally, certain data is only stored in one file but can be linked to data in other files. Data capture needs to be avoided in the preparation of database files because it will result in wasteful use of storage media and allow data inconsistencies to occur.
- Data inconsistency, namely the appearance of inconsistent data in the same area for several files with the same key. This inconsistency may occur due to errors in data entry, namely the process of updating data, but as a result, inconsistent data appears.
- Isolated data, this is caused by the use of several database files. The application program used cannot access certain files in the database system. This isolated data should be avoided because it will result in less complete or less accurate data or information.
- Security Problem, this is related to data security problems in the database system. In principle, database files can only be used by certain users who have the authority to access them. These restrictions are controlled internally in the application program used. The technique that can be used is to use a password, both at the beginning of the process and a layered password that is given at the beginning of each process. Meanwhile, to protect data from damage, data backups can usually be made.
- Integrity Problem, this is related to system performance in order to control all parts of the system so that the system always operates in full control.
According to database experts the meaning of the database is as follows:
- According to Gordon C. Everest
Gordon C. Everest revealed that a database or database is a collection of data that is mechanical, shared, formally defined and controlled. Control of the database system is centralized, which is usually owned and also held by an organization.
- According to CJ Date
Said database or database is a collection of operational data that is intentionally stored and used by the application system of an organization. Date states that the data stored in the database has three types of data, namely: input data, namely data entering from outside the system, output data, namely data generated by the system, while operational data is data stored on the system.
- According to Toni Fabbri
Fabbri, revealed that a database or database is a system where there are many integrated files and data where the files and data have a primary key to perform the data repetition process.
- According to Connolly and Begg (2010: 65)
Connolly and Begg suggest that a database is a distributed set of logically related data, and the explanation of this data is designed to meet the information needs of an organization.
- According to Indrajani (2011)
Several definitions of database, namely:
- A data set that is logically related and is an explanation of the data that is designed with the aim of finding the data needed by a company or organization. The database can also be said to be a collection of data that is competitively integrated because the database is designed to be used by multiple users, holds operational data as well as an explanation of the data, and avoids duplicating data.
- A logically integrated collection of data elements. The database combines various records previously stored in separate files into a data element. According to Connolly & Begg (2010, p65), a database is a collection of logically related data and is designed to fulfill the information needed by an organization.
- Database Functions
For ordinary people, maybe a database is just a collection of data and information that only needs to be backed up for security. But behind that there are other functions of using the database, which are as follows:
- A data can be grouped with the aim of simplifying the data identification process, grouping can be done in various ways such as creating several tables or with different fields. For example, a DBMS in banking can find user information more quickly because it has been grouped respectively.
- Avoid duplicate data being stored. A DBMS software can be set up to be able to recognize the duplication of data that occurs when inputted. This is due to the nature of the database that can be accessed by more than one user. One way to do this is by implementing a system of keywords or Primary Key.
- It makes it easy to use in almost all aspects, such as entering new data, updating or even deleting data that is no longer needed. Supported by the appearance or interface that has been provided using certain applications.
- Being the best solution for using paper as a storage medium that is less effective and takes up a lot of space. With the database, files can be stored digitally.
- A database can also be another alternative regarding the problem of storage space in an application. This is due to the limitations of the storage media by most computer applications.
- Types of Databases
A database generally consists of data that is used by many users, from each user of course has different needs. With this, a database management system can also be grouped into several types with their respective functions and uses. Below are the types of databases, namely:
- Operational Database
This type of database can store detailed data so that it can be operated across an organization. In this sense they can also be called the Subject Area Database (SADB), transaction database or production database. Examples of Operational Databases are customer-used databases, accounting databases and others.
- Relational Database
This type of database is arguably the most popular, this is because by using a Relational Database, users can access or search for information in different tables. The query can also involve multiple tables because of this relation function.
- Distributed Database
As the name implies, this one database can distribute data in a scattered but interconnected manner and can be accessed together. This type of database is usually used in an institution or company that consists of several branches, in order to make it easier for users to access data from one place to another.
- External Database
This database is able to provide access to external parts, the data stored will later be used for commercial purposes. Access to this database will be easier because it is intended for the public and besides that it is also more efficient because there is no need to search for information from the internet.
- Database Terms
Some of the things that are meant by the elements of the database are as follows:
- Entity
An entity is the person, place, event, or concept whose information is recorded. In the health sector the entity is patient, doctor, room.
- Field
Each entity has attributes or designations to represent an entity. A student can be seen from the attributes for example, NIM, Student_Name, Address.
- Record
Record is a collection of contents of data elements (attributes) that are interconnected to inform a complete entity.
Example of a collection of NIP attributes, name, and address containing “01001245566”, Sanusi, Jl. Sacred heart No. 2 Kupang.
- Data Value
Is the actual data or information stored in each data element. The attribute content is called the data value.
- Key Data Element
An identifier that uniquely identifies an entity from a group of entities.
Examples of Student Entities that have npm attributes, name, address, date of birth using the npm Data Element Key.
- Database System Components (Database)
The database is a system consisting of a collection of interconnected files or tables and a Database Management System (DBMS) that allows multiple users to access and manipulate these files (Fathansyah, 1999). The database system has several components, namely:
- Hardware (Hardware)
The hardware that is usually contained in a database system is the secondary memory hard drive.
- Operating System (Operating System)
Operating System (Operating System) is a program that activates or functions the computer system, controls all resources (resources) and performs operations on the computer. Operating systems that are widely used such as: MS-DOS, MS-Windows 95 MS Windows NT, and Unix.
- Database (Database)
A database (Database) can have several databases. Each database can contain or have a number of database objects such as files or tables
- Management System (DBMS)
Physical database processing is not carried out by the user directly, but is handled by a software called a DBMS which determines how data is stored, modified and retrieved.
- User (User)
Users can interact with the database and manipulate data in programs written in a programming language.
- Purpose and Benefits of Database
The main goal in processing data in a database is so that we can get the data we are looking for easily and quickly (Fathansyah, 1999). The use of databases is carried out with the following objectives:
- Speed and ease (Speed)
Utilization of databases allows us to be able to store data or make changes (manipulation) and display the data back quickly and easily, rather than storing data manually.
- Efficient storage space (Space)
With the database the use of data storage space can be done because we can suppress the number of repetitions of data by implementing a number of encodings.
- Accuracy (Acuracy)
Utilization of coding or the formation of relationships between data by applying rules or data type restrictions can be applied in the database which is useful for determining input or storage inaccuracies.
- Security (Security)
In a number of database management systems (applications) do not apply security aspects in database use. But for large and serious systems, the security aspect can also apply. That way we can determine who can use the database and determine what types of operations can be performed.
- Maintaining data alignment (Consitant)
If there is a change in data in a different application, the change will automatically apply to the whole
- Data can be shared (shared)
Data can be shared by several application programs (batch or on-line) at the same time.
- Can be applied standardization (standardization)
With centralized control, the DBA can implement standardization of stored data, making it easier to use, transmit and exchange data.
Weaknesses of Database Systems
- Requires specialist personnel
- Complex
- Requires a large space
- Expensive
- Database Users
- System Engineer
Experts who are responsible for installing the Database System, and also making improvements and reporting errors from the system to the seller
- Database Administrator (DBA)
Experts who have the task of controlling the database system as a whole, forecasting the need for a database system, planning and managing it.
DBA tasks
- Controlling DBMS and softwares
- Monitor who is accessing the database
- Manage database usage
- Checks security, integrity, recovery and concurency
Utility programs used by the DBA:
- Loading Routines, Build the main version of the database
- Reorganization Routines, Organize / reorganize databases
- Journaling Routines, Record all database usage operations
- Recovery Routines, locating data back, before damage occurs
- Statistical Analysis Routines, helps monitor system reliability
- End User
There are several types (types) of users to a database system that can be distinguished based on the way they interact with the system:
- Application programmer
Users who interact with the database via Data Manipulation Language (DML), which are embedded in programs written in the parent programming language (such as C, Pascal, Cobol, etc.)
- Advanced User (Casual User)
Users who interact with the system without writing program modules. They declare a query (for data access) with a query language that has been provided by a DBMS
- General User (End User / Naïve User)
Users who interact with the database system by calling a permanent application program (executable program) that have been written (provided) previously
- Specialized / Sophisticated User
Users who write non-conventional database applications, but for special purposes such as AI applications, Expert Systems, Image Processing, etc., can access the database with or without the DBMS in question.
- Role of Database Systems
The database system in an information system plays an important role where the database is one of the components (sub-systems) that make up the information system and its existence is absolute, where the value and quality of the information system is largely determined by the value and quality of the database system used to compile the system. that information.
- Database system as infrastructure
Information Systems. Database systems and database management systems (DBMS) function as information systems infrastructure built by an organization.
- Database system as a means of effectiveness and efficiency of MIS
The database system will support the effectiveness and efficiency of an organization’s management information system that uses it.
Its effectiveness can be seen from, among others: data compiled and stored in database system files properly (valid), the software used has been tested for reliability (accurate and correct) so that the database system is able to provide great support to the system. information.
Its efficiency can be seen from, among others: the database system is designed and built for various user needs (user needed), easy to use (easy to use), can be used separately or jointly by the user (ready to use), minimizes duplication data (avoiding of redundancy), easy data to modify (database can be modified), can be developed both volume and structure (volume or structure can be developed).
- Definition of DBMS
A Database Management System (DBMS) is a set of computer programs that control the creation, handling, and use of databases. Kroncke at al (1997 and 2007) explained that the Database Management System (DBMS) consists of software that operates the database, provides storage, access, security, back up and other facilities. Database Management System (DBMS) is a system for organizing and processing data bases on computers. This system is designed to be able to perform a variety of data with several references to the same data. This DBMS can be accessed by various applications. Database Management System (DBMS) is a software used to build a computerized database system. The DBMS helps in maintaining and processing large amounts of data sets.
Database management systems can be categorized based on: supported data models, such as “relational databases” or XML, supported computer types, such as “server clusters” or “mobile phones”, languages for accessing databases, such as SQL or Xquery, “trade- ofif “such as” maximum scale or “maximum speed” or others. Some DBMS cover more than categories ie supported by several access languages such as those done in DBMS MySQL, PostgreSQL, Microsoft Access, SQL Server, FileMaker, Oracle, RDBMS, dBASE, Clipper, FoxPro and so on.
- DBMS functions
The services that should be provided by a DBMS are:
- Data storage, retrieval and change
A DBMS must provide the ability to store, retrieve and modify data in a database.
- User accessible catalog
Provides a catalog that contains descriptions of data items stored and accessed by users.
- Supports transactions
Provide a mechanism that will guarantee all changes relating to existing or future transactions.
- Serve concurrency control
A DBMS must provide a mechanism that ensures the database is updated correctly when several users make changes to the same database simultaneously.
- Serving recovery
Provides a mechanism to return the database to a state before the damage occurred to the database.
- Serving authorization
A DBMS must provide a mechanism to ensure that only authorized users can access the database.
- Supports data communication
A DBMS must be able to integrate with communication software.
- Serve integrity
A DBMS aims to ensure that all data in the database and any changes in the data must comply with applicable rules.
- Serving data independence
A DBMS must include facilities to support the independence of the program from a true database structure.
- Serving utilities
A DBMS should provide a collection of utility services.
- DBMS components
- Query Processor
A component that converts query forms into low-level instructions to the database manager.
- The database manager accepts queries and examines the conceptual and external schema to determine whether records are needed to fulfill the request. Then the database manager calls the file manager to complete the request.
- File manager
Manipulate file storage and manage the allocation of storage space on disk.
- DML preprocessor
A module that converts embedded DML into an application program
- RDBMS components
In practice, many database management systems use the “relational model”. Components of the Relational Database Management System, namely:
- Sublanguages, Relational DBMS (RDBMS) including Data Definition Language (DDL) for defining database structures, Data Control Language (DCL) for establishing security / access control, and Data Manipulation Language (DML) for questioning and updating of data,
- Interface drivers, drives are code libraries that provide methods for preparing statements, executing statements, fetching results and so on. Examples: ODBC, JBDC, MySQL / PHP, Firebird / Python.
- SQL engine, this component interprets and executes DDL, DCL and DML statements (including the three main components (compiler, optimizer, and executor),
- Transaction engine, ensures that multiple SQL statements succeed or fail as a group, based on the dictated application,
- Relational engine, relational objects such as tables, indexes, and Referential integrity constraints have been implemented in this component,
- Storage engine, this component stores and retrieves data from second storage, as well as management of transactions that occur and entry, backup and recovery
- Multi User DBMS Architecture
The architectures that are usually used to implement user database systems include:
1) Teleprocessing
The traditional architecture for multi-user systems is teleprocessing, where a computer with a CPU and a number of computer terminals. All processing is done within the same physical computer boundaries. Terminals for ‘dumb’ type users, which cannot function independently and are each connected to a central computer. The terminal sends messages through the communication control subsystem on the operating system to application programs, which in turn use DBMS services. In the same way, messages are returned to the user terminal.
2) File Server
Processes are distributed across a network, a type of Local Area Network (LAN). The file server controls the files required by the application and DBMS. Even though the application and DBMS are run on each workstation but still request files from the file server if needed. In this way, the file server functions as a hard disk that is used simultaneously. The DBMS on each workstation requests data to the file server for all the data the DBMS wants.
3) Client Server
The client server shows how the software components interact in the form of a system. As the name implies, there is a client processor that requires resources and a server that provides the source. The server is placed on one side of the LAN and the client on the other.
- Data Management in the DBMS
Data needs to be stored in databases for the purposes of providing further information. The data in the database needs to be organized in such a way so that the quality information produced is produced. Good database organization is also useful for efficiency of storage capacity.
In the same sense, it can also be interpreted as a collection of information arranged in such a way as to be accessible by a particular software. A database is composed of sections called fields and records that are stored in a file. A field is the smallest unit of information in a database. A set of related fields will form a record.
- Language in the DBMS
To interact with the DBMS (database), use the database language specified by the DBMS company. The database language usually consists of commands that are formulated so that these commands will be processed by the DBMS. Commands are usually defined by the user. There are 2 database languages:
1) Data Definition Language (DDL)
DDL is used to describe the overall database design. DDL is used to create new tables, load indexes, or modify tables. The results of the DDL compilation are stored in the data dictionary.
2) Data Manipulation Language (DML)
DML is used to manipulate and retrieve data in a database such as adding new data to the database, deleting data from a database and changing data in a database.
- Views in the DBMS
One of the goals of the DBMS is to provide a user interface in terms of conveying data. For this reason, in the DBMS there is a Data Abstraction Level. This level is useful for hiding the details or complexity of the database such as how the data is stored and processed. So that users only see the display that the user needs.
1) Physical level
Physical level is the lowest level. This level shows how the data is actually stored.
2) Conceptual Level
This level describes how the database is actually stored and related to other data
3) Level View
This level of abstraction represents only a portion of the database. In general, users do not involve directly so that users only see data as needed.
- Benefits and advantages of using DBMS
Benefits and advantages of DBMS data storage in the form of DBMS has many benefits and advantages compared to storing in flat files or spreadsheets, including:
1) The performance obtained by storing in the form of a DBMS is quite large, very much different from the performance of data stored in the form of a flat file. Besides having better performance, you will also get efficient use of storage media and memory.
2) Data integrity is guaranteed by using a DBMS. Redundancy problems often occur in DBMS. Redundancy is the occurrence of repetition of the same data or data set in a database which results in waste of storage media.
3) Independence. Changes in database structure are possible without having to change the applications that access them, so that making interfaces into data will be easier with the use of a DBMS
4) Centralization. Centralized data would simplify database management. The ease of sharing with the DBMS and also the consistency of data accessed together will be more guaranteed than data stored in the form of files or spreadsheets.
5) Securities. DBMS has a more flexible security system than the security of operating system files. Security in the DBMS will provide flexibility in granting access rights to users.
