Data modeling

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  • Advantages And Disadvantages Of A Relational Table

    the underlying base tables whenever it’s accessed. These present only a subset of the database that is of particular interest to a user. Views can be customized, for example, field names may change, and they also provide a level of security preventing users from seeing certain data. Advantages and disadvantages of DBMSs. Some advantages of the database approach include control of data redundancy, data consistency, sharing of data, and improved security and integrity. Some disadvantages include complexity, cost, reduced performance, and higher impact of a failure. (a) relation A table with columns and rows. (b) attribute A named column of a relation. (c) domain The set of allowable values for one or more attributes. (d) tuple A record of a relation. (e) relational database A collection of normalized tables Properties of a relational table. A relational table has the following properties: 0 The table has a name that is distinct from all other tables in the database. 1 Each cell of the table contains exactly one value. (For example, it would be wrong to store several telephone numbers for a single branch in a single cell. In other words, tables don’t contain repeating groups of data. A relational table that satisfies this property is said to be normalized or in first normal form.) 2 Each column has a distinct name. 3 The values of a column are all from the same domain. 4 The order of columns has no significance. In other words, provided a…

    Words: 7343 - Pages: 30
  • Relational Database Case Study

    What is a relational database? It is a database that stores the information about both data, for example for a person detail that is link with their car details that they have bought it from the company. The data and relationships are showed in an entity which is in a flat, two dimensional tables. We would use a relational database in a company such as a car company so when they want to store their customers information and what car did they buy, they use a relational database which stores the…

    Words: 736 - Pages: 3
  • Reproduction Antiques Company Case Study

    client, in our case The Reproduction Antiques Company. It is a conceptual level data model and provides the concepts of entities, relationships and attributes. The Reproduction Antiques Company database context Entity: an animate or inanimate thing of independent physical or conceptual existence and distinguishable.…

    Words: 853 - Pages: 4
  • Database Management And Information Retrieval System Case Study

    adding, deleting, and modifying data A built-in user interface that carry the activity of obtaining information resource from a collection of information stored EXAMPLE Microsoft Access, MySQL, Oracle, and Microsoft SQL Server Web search engine ADVANTAGES -Controlling data redundancy -Data consistency -Data sharing -Data integration -Integrity constraints -Data atomicity -Database access language -Development of application -Creating forms -Report…

    Words: 1607 - Pages: 7
  • Meaning Of Database Management System

    Definition of Data: The term data is known as representation of objects, events which are stored and recorded in the computer and the data exists in a variety of forms such as values, variables and numbers and so on etc. EX: The database in a hospital contains data such as name of the patient, address, disease and contact number. Definition of Database: The term database is determined as data collection in an organized manner and every data present is related to each other in some other way.…

    Words: 815 - Pages: 4
  • Data Integrity And Data Warehouse

    Data integrity ensures that data is ultimately accurate. This is important when trying to analyze data that is stored in the database or data warehouse. Inaccurate data will lead to false results in reporting and analytics that will affect any business decisions that need to be made. When dealing with data integrity, having the full or complete set of data is a necessity. If only half or some of the data is entered than it cannot be considered accurate. There are several ways to ensure that data…

    Words: 1257 - Pages: 5
  • CRUD: Defining Information Ownership Analysis

    and delete – matrix as it relates to student information and the individuals or departments related to the school that may require access. The resulting model will be used to interpret business rules and explain how they relate to the components of a relationship database model. CRUD – Create, Retrieve, Update and Delete Purdue (2014) suggests the use of the CRUD two-dimensional table to visually summarize data usages by function. In the student/school relationship model, one possible…

    Words: 778 - Pages: 4
  • Mongodb Case Study

    Caution No blank lines is allowed in the MongoDB Script Sampler. If there is a blank line after MongoDB statement, the statement will still be executed but the word “ok” will be displayed in the response. Add new document into the collection Step 1 Change the “Script” area of the MongoDB Script sampler with insert query. In this case, the query of adding document into the collection is shown as follows: db.getCollection('zips').insert({"city" : "BABYLON", "loc" : [ 32.211100, 44.251500 ],…

    Words: 253 - Pages: 2
  • Advantages And Disadvantages Of The Hierarchal Database

    Hierarchal Database “In the network model, the data are represented by collections of records and relationships between data are represented by links. This structure holds for the hierarchical model as well. The only difference is that, in the hierarchical model, records are organized as collections of trees, rather than as arbitrary graphs.”(http://codex.cs.yale.edu/avi/db-book/db6/appendices-dir/e.pdf, 17-10-2014) This database model use rules as each child has one parent and each parent can…

    Words: 938 - Pages: 4
  • Advantages And Disadvantages Of The Database Management System

    is “A shared collection of logically related data, and a description of this data, designed to meet the information needs of an organization”. The Database Management System (DBMS) is software that enables users to define, create, maintain and control access to the database. The database has identified three levels of abstraction. All these three levels will have different aspects and they are as follows: • Physical or external level- The database system can show for the users the part of the…

    Words: 1307 - Pages: 6
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