- Define macro, primary key, secondary key, record and their uses
- A macro is a rule or sequence that states how a certain sequence or pattern should be mapped to an output sequence according to a specific method. The mapping process is called the macro expansion. It is what transforms a macro into a certain specified output sequence. In order for programmers to use make their tasks less tedious and error-prone, a macro could be used as a sequence of computing instructions as a single program statement would allow it to be more consistent.
- Primary Key: In databases such as relational database designs, a primary key that is also referred to as a unique key, can identify each row in a table. A primary key comprises of a single column or a set of columns. Depending on its design, a table may have many unique keys but at most one primary key. A primary key is useful while making a database for a school. Each and every student ID number would be suitable for a primary key of the table as each student of the school would have a different ID number.
- Secondary Key: A secondary key is also known as an alternate key. It is the key that carries the physical location of a record in a database. It provides an alternative path in accessing the data. A secondary key is useful when looking for an alternative to searching for the records with a primary key.
- Record: A record is a collection of data or information arranged in a database. In a database, a record is usually referred to as a row which is a group of fields within a single table. For example in a table called Student Contact information, a row would contain fields such as; ID number, Name, Telephone Number, etc. Multiple records are usually contained in a file.
- Discuss one paragraph for each:, web databases, online encyclopedias
- Web Databases: A web database is a broad term for managing data online. It gives one the ability to build their own database without being a genius in the field of technology. It allows one to store critical information in the web database where it can be easily accessible to everyone. It increases the efficiency and communication for the people that need to view such information. The common uses of web databases may be web site polls, feedback forms, party invitations, etc.
- Online Encyclopedias: As technology has advanced, encyclopedias have advanced from being stacked in bookshelves to being available on the net. An encyclopedia being a reference book that covers all branches of knowledge or one main branch can now be easily and globally accessible online. Examples of online encyclopedia’s include; Britannica encyclopedia, Wikipedia, Encarta Online Encyclopedia, etc.
- Explain Data integrity, reliability, redundancy,Data matching, data mining, Database security
- Data Integrity: Data Integrity refers to the accuracy and consistency of the data that is stored. It is indicated by an absence of any alteration in the data between any recent updates of the record. It is usually imposed within a database at its design stage through validation checks such as error checking and proofreading of the data.
- Reliability: Data reliability is a state in which all the data is fully complete and is error free. The reliability of data consists of entering the reliability of the database at different phases of the creation of a database. The reliability of data is an essential for the validity of data.
- Redundancy: Data redundancy occurs in databases which have a field that is repeated in other tables. Data redundancy can be avoided at the design stage of the database by designing the database according to its requirements. By designing the database properly, data anomalies and data corruption can be avoided. Another way of preventing data redundancy, normalization of the data should be implemented in order to make the best of the storage capacity of the system. Moreover, by using suitable foreign keys in a database could reduce the chances of redundancy and anomalies.
- Data Matching: Data Matching is a powerful administrative and law enforcement tool that allows information from various sources to be combined and brought together to a wide range of public policy purposes.
- Data Mining: Data mining is the process of obtaining patterns from large data sequences by putting together statistical methods and artificial intelligence with appropriate database management. It is said to be an increasingly important tool in terms of modern business to the transformation of data into business intelligence that gives an informational advantage. For example: it is used in marketing, surveillance, scientific discovery, fraud detection, etc.
- Database Security: Since databases contain all the information one may need to know about a school, company or corporation, their databases need to be secure. By conducting inference tests, testing for vulnerabilities and decryption of the database, the database may be free from hackers and other security hazards.
- Identify three issues in question 3(see above) and discuss them.
- Database Security: The issue regarding the security of data would be linked to the necessity to implement various systems and software’s in order to protect the data from any collateral damage or theft. Implementing such software’s may be an issue in terms of cost as the software’s to be implemented may be costly and thus the company will be required to invest a lot of money.
- Database Integrity: A concerning issue regarding the integrity of data would be that if the data in a database was threatened by environmental hazards, heat, dust and electrical surges, recovery of data lost may be problem.
- Data Redundancy: The process of normalization of redundant data is a long one as each record would have to be crosschecked and thus the factor of time may be an issue.
- http://www.blurtit.com/q543686.html
- http://www.libraryspot.com/features/encyclopedia.htm
- http://hsc.uwe.ac.uk/dataanalysis/quantIssuesValid.asp
- http://download.oracle.com/docs/cd/B19306_01/server.102/b14220/data_int.htm
- http://en.wikipedia.org/wiki/Macro_(computer_science)
- http://databases.about.com/cs/administration/g/primarykey.htm
- http://www.computerhope.com/jargon/s/seconkey.htm
- http://searchoracle.techtarget.com/definition/record
- http://www.britannica.com/
good. give the source also if you have used any.
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