Preview

Master in It

Powerful Essays
Open Document
Open Document
1060 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Master in It
Short Answered Questions:

1. What is the purpose of having foreign key(s) in a relational database table?

i. Represent a relationship between tables ii. Foreign key in one table has the same value, referencing another table’s primary key iii. Referential integrity

2. What is the purpose of having a primary key in the relational database table?

i. Primary key is used as a unique identifier to represent the data in that row. ii. It is also used to provide a link to related tables (by being used as a foreign key). iii. The primary key MUST determine all non-key attributes.

3. How are relationships between tables expressed in a relational database?

i. Use of embedded foreign keys ii. Use of a separate relation table

4. When do you have to use an “intersection entity” and what is it?

“Intersection entity” is an entity used in order to resolve M to M relationships. M-M relationships can be converted to a pair of one to many relationships by creating an intersection entity that contains one occurrence for each related pair. In general it means that a primary key from each entity becomes a part of the composite key for the intersection entity.

5. Briefly explain what would be main advantages of your newly created database system over an existing spreadsheet?

i. Avoids update, insert and delete anomalies ii. Avoids data redundancy iii. Better design structure, security, data independence

6. Database Management Systems contains two main parts in a database: data and meta-data. What is meta-data?

Data only becomes useful when placed in some context. The primary mechanism for providing context for data is meta-data. Mata-data is data about data. It describes the properties or characteristics of other data. Some of these properties include data definitions, data structures and rules or constraints.

7. What is a Database?

A

You May Also Find These Documents Helpful

  • Good Essays

    Questions Unit 2 Pt2520

    • 389 Words
    • 2 Pages

    * Surrogate Keys or Natural Keys? By Craig S. Mullins - Posted Sep 11, 2012 - September 2012 Issue http://www.dbta.com/Articles/Columns/DBA-Corner/Surrogate-Keys-or-Natural-Keys-84892.aspx…

    • 389 Words
    • 2 Pages
    Good Essays
  • Better Essays

    Normalization of the database: This is a critical step for making the database. Normalization will help create table structures as well…

    • 3100 Words
    • 13 Pages
    Better Essays
  • Powerful Essays

    Database Environment

    • 1121 Words
    • 5 Pages

    When building a system for information, you have to decide how much responsibility for data management your software will take. A database can be rather large or it can be small depending on the information that is being stored. Request for information from a database are made in the form of a query or a question asking the database for particular information. All database management systems are not the same from a technical standpoint. They differ mostly in the way they organize their information internally. The internal organization can then determine how quickly and supplely the information can be extracted (Jupitermedia, 2011) .…

    • 1121 Words
    • 5 Pages
    Powerful Essays
  • Satisfactory Essays

    10. What purpose does a primary key serve in a table? It serves as the identifier for that table.…

    • 421 Words
    • 2 Pages
    Satisfactory Essays
  • Powerful Essays

    data to be ready for producing meaningful output from the DBMS?d) 5 What are two main forms of output from a DBMS? Provide one example of each form of output using…

    • 1445 Words
    • 6 Pages
    Powerful Essays
  • Good Essays

    Anime LIst

    • 11441 Words
    • 52 Pages

    Which of the following defines a relationship in which each occurrence of data in one entity…

    • 11441 Words
    • 52 Pages
    Good Essays
  • Good Essays

    07

    • 4772 Words
    • 25 Pages

    5) The SQL keyword CONSTRAINT is used in conjunction with the SQL keywords PRIMARY KEY and FOREIGN KEY.…

    • 4772 Words
    • 25 Pages
    Good Essays
  • Satisfactory Essays

    Entity-relationship Model

    • 411 Words
    • 2 Pages

    12. Linking Entities- Linking entities are used to resolve many-to-many relationships into two one-to-many relationships.…

    • 411 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    • Note. A key is a unique identifier that distinguishes rows within a database table. To view examples, please refer to your text.…

    • 103 Words
    • 1 Page
    Satisfactory Essays
  • Good Essays

    Master Patient Index

    • 432 Words
    • 2 Pages

    The Primary Key is a Key in a database that is unique for each record and identifies patients. This Key can be a driver’s license, a social security number, or a telephone number. The database can only have one type of Key for each record, otherwise it would be too confusing to search for patient records.…

    • 432 Words
    • 2 Pages
    Good Essays
  • Satisfactory Essays

    MS Access - Part 1

    • 468 Words
    • 2 Pages

    1. Raw data that has been organized so as to become useful is also known as…

    • 468 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    Lab 204 Quiz

    • 2478 Words
    • 10 Pages

    You follow certain step’s to access the supplementary readings for a course when u sing your organizations library management system. These steps that you follow are examples of the _________ components of an information system.…

    • 2478 Words
    • 10 Pages
    Satisfactory Essays
  • Good Essays

    List the relational operators and logical operators that can be used to form a validation rule.…

    • 636 Words
    • 3 Pages
    Good Essays
  • Satisfactory Essays

    Answer Case 342

    • 403 Words
    • 2 Pages

    4. You have probably noticed that the Stillwater students chose to include a stamp field as part of the primary key for all of the relations except product. Explain why you think they decided to include this field in each relation and why it is part of the primary key. Are there other alternatives to a time stamp field for creating the primary key of this relation?…

    • 403 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    What Is Super Key in Dbms

    • 1055 Words
    • 5 Pages

    A superkey is a combination of attributes that can be uniquely used to identify a database record.With primary key if any other attribute is added then that combination is called super key in other words,primary key is the minimum possible...…

    • 1055 Words
    • 5 Pages
    Satisfactory Essays