Preview

Questions Unit 2 Pt2520

Good Essays
Open Document
Open Document
389 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Questions Unit 2 Pt2520
Unit 2
Homework Questions
Alvaro Ojeda
PT 2520

Instructor
Mrs. Hubbard 1. What is a database requirement?

* The requirements for a logical and physical database vary by size and design parameters. A logical database must be able to access and identify all files within the storage system to operate correctly, whereas a physical database manages a much smaller field of information. Sometimes, a physical database stores only a single file with one value or word in it.

2. What is the primary purpose of a report?

* A document used to display summarized or formatted data.

3. What is the primary purpose of a form?

* A document that is used to gather data.

4. What is the domain of a database?

* This is the focus of the database.

5. What is work shadowing?

* It means following and observing persons as they go through their work routine.

6. What is a candidate key?

* A Candidate Key can be any column or a combination of columns that can qualify as unique key in database. There can be multiple Candidate Keys in one table. Each Candidate Key can qualify as Primary Key.

7. What is a composite key?

* A key that consist of more than one attribute.

8. What is a natural key?

* A key made from one or more of an entity’s “natural” attributes.

9. What are the advantages of a natural key?

* Natural keys prevent duplicate rows, because the attributes are part of the primary key. Any duplicate set of data will be rejected from being inserted by plain primary key logic (unique and not null). This dramatically increases the overall data quality compared to artificial keys.

10. What is a surrogate key?

* An artificially created key, often just auto-incremented numbers

11. What is a stakeholder?

* Anyone with a “stake” in the final product. Anyone who will use or be affected by the database.

12. What is an exception (with regard to a database)?



References: * Hands-On Database -Steve Cogner2012 Pearson Education Inc. * Logical and Physical Database Requirements by Jonathan Lister , Demand Media http://smallbusiness.chron.com. * 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

You May Also Find These Documents Helpful

  • Satisfactory Essays

    The column specification that determines what kind of data can be stored in that column, character versus numeric or date, for example.…

    • 327 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    This memo is to inform you that your service request SR-ta-001 has reached my desk and currently is in the process of being completed. The purpose of this memo is to report the progress on the service requests. Currently I am in the stage of normalizing the database to the third normal form. By normalizing the database to the third level of normalization I will ensure that the data is efficiently organized within the database by removing duplicate and redundant data from the database relations. Normalizing the data to the normal third will help free up space and make it easier for the users to retrieve the data by elimination of the same data stored in more than one relation. In addition, normalizing to this level will also ensure data integrity, scalability, and storage efficiency. I have made sure that that there are no repeating columns or rows within the same tables and each column has only one value and one data type therefore the level of 1 normalization has been completed. I then continued to normalize the database to the second level of normalization by ensuring that each nonkey attribute is fully dependent on the key columns of the table. Once level one and two normal form had been completed I continued by establishing primary and foreign keys along with relationships. I will keep in contact with you as the project nears completion.…

    • 329 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    04

    • 4586 Words
    • 34 Pages

    Constraints are used to ensure the accuracy and integrity of the data contained in the database.…

    • 4586 Words
    • 34 Pages
    Satisfactory Essays
  • Satisfactory Essays

    Week 3

    • 754 Words
    • 4 Pages

    assigning attributes to the data. creating an inventory of data contained in the database. presenting data as end users or…

    • 754 Words
    • 4 Pages
    Satisfactory Essays
  • Powerful Essays

    A characteristic, for example; a field has many attributes such as data like numbers or letters. Attributes can be used as a synonym for a “field”. In DOS systems, each files has an attribute, each file has many properties that shows if the file is “read only”, visible or encrypted.…

    • 1351 Words
    • 5 Pages
    Powerful Essays
  • Good Essays

    Explain referential integrity and the purpose of primary keys in building the relationships between tables…

    • 1421 Words
    • 8 Pages
    Good Essays
  • Good Essays

    There are a series of guidelines that ensure the database is normalized. They are refered to as normal forms and are numbered from one (the lowest form) through five, althought the fifth form is rarely seen. The normal forms of relational database theory provide criteria for determining a table’s degree of vulnerablility to logical inconsistencies and anomalities. The higher the normal form, the less vulnerable it is to inconsistencies…

    • 505 Words
    • 3 Pages
    Good Essays
  • Good Essays

    For example, the customer table will have a primary key which is individual for each customer. This key can then be referenced by the customer order table which maintains order history for all customers. The products table can use the same process to access inventory counts and/or supplier information. All of this…

    • 666 Words
    • 3 Pages
    Good Essays
  • Powerful Essays

    This article begins with an introduction to relational database design theory, including a discussion of keys, relationships, integrity rules, and the often-dreaded "Normal Forms." Following the theory, I present a practical step-by-step approach to good database design.…

    • 7444 Words
    • 30 Pages
    Powerful Essays
  • Satisfactory Essays

    Data Integrity

    • 500 Words
    • 3 Pages

    A primary key value rule defined on a key (a column or set of columns) specifies that each row in the table can be uniquely identified by the values in the key.…

    • 500 Words
    • 3 Pages
    Satisfactory Essays
  • Good Essays

    Another advantage of normalization is that it provides indexing. Indexing speeds up the access of data, increase delete, update, and insert performance. Normalization also minimizes modification anomalies. Modification anomalies can occur when the data is deleted, inserted, or updated, and the data is lost in other ways such as hardware being damaged or stolen. In addition, normalization helps with the reduction of table and row size. Creating primary and foreign key constraints will reduce the number of empty or null values in columns and reduces the overall size of the database. Normalization has yet another great advantage, referential integrity. Referential Integrity means that one column…

    • 677 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Database Design

    • 661 Words
    • 2 Pages

    In this essay I'm going to be discussing what database systems are and how they are used. I will de speaking on and defining database architecture. I also will be discussing how database systems are used in my everyday life and at my workstation.…

    • 661 Words
    • 2 Pages
    Good Essays
  • Powerful Essays

    Normalization

    • 4768 Words
    • 20 Pages

    Tables that contain redundant data can suffer from update anomalies, which can introduce inconsistencies into a database. The rules associated with the most commonly used normal forms, namely first (1NF), second (2NF), and third (3NF). The identification of various types of update anomalies such as insertion, deletion, and modification anomalies can be found when tables that break the rules of 1NF, 2NF, and 3NF and they are likely to contain redundant data and suffer from update anomalies. Normalization is a technique for producing a set of tables with desirable properties that support the requirements of a user or company. Major aim of relational database design is to group columns into tables to minimize data redundancy and reduce file storage space required by base tables. Take a look at the following example:…

    • 4768 Words
    • 20 Pages
    Powerful Essays
  • Good Essays

    What is a primary key? A candidate key to uniquely identify other columns in the relation…

    • 628 Words
    • 3 Pages
    Good Essays
  • Powerful Essays

    Nosql

    • 1273 Words
    • 6 Pages

    * The basic key/value store performs nothing other than the function described above – taking a binary data object, associating it with a key, and storing it in the database for later retrieval.…

    • 1273 Words
    • 6 Pages
    Powerful Essays

Related Topics