QUIZ 8
1. A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality (for example, the availability of rooms in hotels), in a way that supports processes requiring this information (for example, finding a hotel with vacancies). The term "database" refers both to the way its users view it, and to the logical and physical materialization of its data, content, in files, computer memory, and computer data storage. This definition is very general, and is independent of the technology used. However, not every collection of data is a database; the term database implies that the data is managed to some level of quality (measured in terms of accuracy, availability, usability, and resilience) and this in turn often implies the use of a general-purpose Database management system (DBMS). A general-purpose DBMS is typically a complex software system that meets many usage requirements, and the databases that it maintains are often large and complex.
The term database is correctly applied to the data and data structures, and not to the DBMS which is a software system used to manage the data. The structure of a database is generally too complex to be handled without its DBMS, and any attempt to do otherwise is very likely to result in database corruption. DBMSs are packaged as computer software products: well-known and highly utilized products include the Oracle DBMS, Access and SQL Server from Microsoft, DB2 from IBM and the Open source DBMS MySQL. Each such DBMS product currently supports many thousands of databases all over the world. The stored data in a database is not generally portable across different DBMS, but can inter-operate to some degree (while each DBMS type controls a database of its own database type) using standards like SQL and ODBC. A successful general-purpose DBMS is designed in such a way that it can satisfy as many different applications and application designers as possible. A DBMS also needs to provide effective run-time execution to properly support (e.g., in terms of performance, availability, and security) as many end-users (the database's application users) as needed. Sometimes the combination of a database and its respective DBMS is referred to as a Database system (DBS).
A database is typically organized according to general Data models that have evolved since the late 1960s. Notable are the Relational model (all the DBMS types listed above support databases based on this model), the Entity-relationship model (ERM; primarily utilized to design databases), and the Object model (which has more expressive power than the relational, but is more complicated and less commonly used). Some recent database products use XML as their data model. A single database may be viewed for convenience within different data models that are mapped between each other (e.g., mapping between ERM and RM is very common in the database design process, and supported by many database design tools, often within the DBMS itself). Many DBMSs support one data model only, externalized to database developers, but some allow different data models to be used and combined.
The design and maintenance of a complex database requires specialist skills: the staff performing this function are referred to as database application programmers (different from the DBMS developers/programers) and database administrators, and their task is supported by tools provided either as part of the DBMS or as free-standing (stand-alone) software products. These tools include specialized Database languages including Data Description Languages, Data Manipulation Languages, and Query Languages. These can be seen as special-purpose programming languages, tailored specifically to manipulate databases; sometimes they are provided as extensions of existing programming languages, with added special database commands. Database languages are generally specific to one data model, and in many cases they are specific to one DBMS type. The most widely supported standard database language is SQL, which has been developed for the relational model and combines the roles of Data Description Language, Data manipulation language, and a Query language.
A way to classify databases involves the type of their contents, for example: bibliographic, document-text, statistical, multimedia objects, etc. Another way is by their application area, for example: Accounting, Music compositions, Banking, Manufacturing, Insurance, etc.

2. File maintenance refers to the procedures that keep data current. File maintenance procedures include adding records to correct inaccurate data or to update old data with new data, and deleting records when they no longer are needed. Validation is the process of comparing data with a set of rules or values to find out if the data is correct. Many programs perform a validity check that analyzes data, either as you enter it or after you enter it, to help ensure that it is correct. Types of validity checks include an alphabetic check, a numeric check, a range check, a consistency check, a completeness check, and a check digit.

3. Character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syllabary in the written form of a natural language.
Field (also called data member or member variable) is the data encapsulated within a class or object.
Records (also called tuples, structs, or compound data) are among the simplest data structures. A record is a value that contains other values, typically in fixed number and sequence and typically indexed by names. The elements of records are usually called fields or members.
Computer file is a block of arbitrary information, or resource for storing information, which is available to a computer program and is usually based on some kind of durable storage. A file is durable in the sense that it remains available for programs to use after the current program has finished. Computer files can be considered as the modern counterpart of paper documents which traditionally are kept in offices' and libraries' files, and this is the source of the term.

4. Data dictionary, or metadata repository, as defined in the IBM Dictionary of Computing, is a "centralized repository of information about data such as meaning, relationships to other data, origin, usage, and format." The term may have one of several closely related meanings pertaining to databases and database management systems (DBMS): 

• a document describing a database or collection of databases
• an integral component of a DBMS that is required to determine its structure
• a piece of middleware that extends or supplants the native data dictionary of a DBMS

File maintenance is a procedure that keeps computer files current by applying all necessary transactions (adjustments) against the file. A file maintenance procedure must be performed prior to generating any output, such as labels, reports, or list rental selections, from the file. Transactions include changes of address, addition and deletion of records, application of payments to credit orders, and so forth. In on-line systems, file maintenance is performed continuously. In batch systems, it is scheduled according to the frequency with which output must be generated. File retrieval is the process of salvaging data from damaged, failed, corrupted, or inaccessible secondary storage media when it cannot be accessed normally. Often the data are being salvaged from storage media such as internal or external hard disk drives, solid state drives (SSD), USB flash, storage tapes, CDs, DVDs, RAID, and other electronics. Recovery may be required due to physical damage to the storage device or logical damage to the file system that prevents it from being mounted by the host operating system.

Data security is the means of ensuring that data is kept safe from corruption and that access to it is suitably controlled. Thus data security helps to ensure privacy. It also helps in protecting personal data.
Backup or the process of backing up is making copies of data which may be used to restore the original after a data loss event. The verb form is back up in two words, whereas the noun is backup.
Backups have two distinct purposes. The primary purpose is to recover data after its loss, be it by data deletion or corruption. Data loss is a very common experience of computer users. 67% of internet users have suffered serious data loss. The secondary purpose of backups is to recover data from an earlier time, according to a user-defined data retention policy, typically configured within a backup application for how long copies of data are required.
Though backups popularly represent a simple form of disaster recovery, and should be part of a disaster recovery plan, by themselves, backups should not alone be considered disaster recovery. Not all backup systems and/or backup applications are able to reconstitute a computer system, or in turn other complex configurations such as a computer cluster, active directory servers, or a database server, by restoring only data from a backup.

5. A database co-ordinate the physical and logical access to data while a file - processing system only co-ordinates physical access to the data

6. Relational database matches data by using common characteristics found within the data set. The resulting groups of data are organized and are much easier for many people to understand.

For example, a data set containing all the real-estate transactions in a town can be grouped by the year each transaction occurred, the sale price, a buyer's last name and so on. Such a grouping uses the relational model (a technical term for this is schema). Hence, such a database is called a "relational database."

The software used to do this grouping is called a relational database management system (RDBMS). The term "relational database" often refers to this type of software.

Relational databases are currently the predominant choice in storing data like financial records, medical records, personal information and manufacturing and logistical data.

Object database (also object-oriented database management system) is a database management system in which information is represented in the form of objects as used in object-oriented programming. Object databases are a niche field within the broader database management system (DBMS) market dominated by relational database management systems. Object databases have been considered since the early 1980s and 1990s, but they have made little impact on mainstream commercial data processing, though there is some usage in specialized areas. 

Multidimensional database (MDB) is a type of database that is optimized for data warehouse and online analytical processing (OLAP) applications. Multidimensional databases are frequently created using input from existing relational databases. Conceptually, a multidimensional database uses the idea of a data cube to represent the dimensions of data available to a user. For example, "sales" could be viewed in the dimensions of product model, geography, time, or some additional dimension. In this case, "sales" is known as the measure attribute of the data cube and the other dimensions are seen as feature attributes. Additionally, a database creator can define hierarchies and levels within a dimension (for example, state and city levels within a regional hierarchy).

7.Using the Microsoft Visual Web Developer Web development tool, you can create Web pages that work with data from a variety of sources, including databases, XML files, and business objects. This walkthrough shows you how to work with data in a Microsoft Access database. Access databases do not have the same capacity and are not as scalable as other types of databases, such as Microsoft SQL Server. Generally, if you are creating a Web site that will support only light traffic or a limited number of users, an Access database is sufficient. However, if the Web site will support more throughput or a larger number of users, you should consider using SQL Server or another database that is suited for production Web sites.

8. Cyberterrorism is the use of Internet based attacks in terrorist activities, including acts of deliberate, large-scale disruption of computer networks, especially of personal computers attached to the Internet, by the means of tools such as computer viruses, cyberextortionist, and cyberterrorist.    

Computer security is a branch of computer technology known as Information Security as applied to computers and networks.

Types of perpetrators:

A hacker is a person who breaks into computers and computer networks for profit, in protest, or because they are motivated by the challenge.

Cracker, sometimes white cracker, is a pejorative term for white people.

Script kiddie or skiddie, is a derogatory term used to describe those who use scripts or programs developed by others to attack computer systems and networks and deface websites

Computer Spies are interested in information, not just computers

Cyberextortionist are criminals increasingly using a method known as Distributed Denial of Service (DDOS) attacks.

Cyberterrorism is the use of Internet based attacks in terrorist activities, including acts of deliberate, large-scale disruption of computer networks, especially of personal computers attached to the Internet, by the means of tools such as computer viruses

9. While designing a relational database, it is a good idea to distribute the information in multiple tables. It is not advisable to store all the information in a single table, although it is easier to design. When your database grows in size, the efficiency decreases accordingly, For example, if you are planning to make a simple database of your employees, then you can divide the employees’ information in 3 tables. In one table you can store the contact info, in second you can store the salary and department details and in third table you can store the bonus history of the employees

10. Through Operating system and software patches and updates, Passwords, Get a hardware or software firewall, Get a hardware or software firewall, Get a hardware or software firewall, Get a hardware or software firewall and Get a hardware or software firewall.