Logical and Physical Data Models

Data objects can model relational data or advanced data types such as graphics, movies, and audio. Smalltalk, C++, Java, and others are objects used in object-oriented data. The object-relational is a combination of relational and object-oriented databases. Traditional and advanced data types can be used to construct database management systems. These systems can connect to a company’s website and update records as needed. Database Approach The main purpose of a database is data storage that can be stored and retrieved when needed. A popular common language called structured query language (SQL) is used to store and retrieve data in relational database. This language enables the systems to run a report or modify data or remove the data from the database. A database management system (DBMS) controls all aspects of a database, this is not limited to the creation, maintenance, and use of database. The DBMS ensures proper applications are able to access the database. An important purpose of a DBMS is to maintain the data definitions (data dictionary) for all the data elements in the database. It also enforces data integrity and security measures. Data Models Data models provide a contextual framework and graphical representation that aid in the definition of data elements. In a relational database, the data model lays the foundation for the database and identifies important entities,

This is a pictorial representation of the real world problem in terms of entities (which have attributes) and relations between the entities is referred to as ER diagram.

2. using the data requirements and the business rules provided, develop a conceptual model (ERD), including attribute data types and required field lengths; and

The data structure represents the logical relationships between data elements. In addition the data also determines the organizational structure, access methods, and alternative processing assosiativitas level for information.

Database model defines the logical structure of the database by determining manner in which the data will be stored. Relational model is one of the most popular database models, which defines tables and relationships between the tables.

The conceptual model will have all of the attributes from the students as well as the instructors. It will also have the all of the constraints. This model will have software and hardware independency. At this level any changes to the database management system will not affect this model. The physical model will take all the information that comes from the conceptual model and describe it so that it can be saved and stored. This model will need to know the physical storage device and access method so that it can reach the information stored in the devices. The physical model, not like the conceptual, will be both software and hardware

32) Because SQL statements are table-oriented, whereas programs are variable-oriented, the results of SQL statements used in programs are treated as pseudofiles.

This model demonstrates the data attributes logical entities and relationships between these entities within a business function. It also helps to create the physical data model. Moreover, it shows more details while integrate business logic and business rules. This model is used to describe the domain concept and their relationship of the domain problem.

Logic models represent a visual way of expressing the rationale or thought behind a program. Two other forms of expression may help concurrently support the development of a logic model, or accompany the model if it is to be communicated through written materials.

There are several important steps to consider when designing a database, as a well-designed database should be deployed and not only support the accuracy and integrity of business information but also avoid redundant data and assist with has enterprise level reporting tasked. If we analyze the

Logical and physical models represent the key elements and processes of the software development. The logical model describes the processes, and data, in as much detail as possible, without giving regard to how the system will be implemented. Logical data models include

A database is used to store collections of information and easily retrieved at a later date. The larger the amount of information, the more organized a database needs to be. A database is created with the requirements and needs of current and future users and most importantly, with past users and their information. Out book defines database systems as “an organization of components that define and regulate the collection, storage, management, and use of data within a database environment”. (Database Systems, 2013)

A _______________ is an overall logical view of the relationships among the data elements in a database.

Relational database contains data records that do not have a preset of relationships, permitting the user to define his or her relationship when accessing the data. Since users have much control over the data being accessed, relational databases can perform a variety of tasks. Such as defining the database; querying the database; adding, editing, and deleting data from the database; modifying the structure of the database; securing data from public access; communicating within the network; and exporting and importing data (Murthy, 2008).

Databases are the center of many technology and non-technology focused businesses. They are used in retail, healthcare, education and government. Databases are essentially in entering, storing, managing and referencing data, and can be simple in nature, or extremely complex. In order for a database to be implemented correctly, planning is required. Planning takes place from the moment of idea inception, and continues throughout multiple stages of the planning process (typically during the analysis and design phases). An Entity-relationship diagram, or ERD, is a visual layout or plan for a database. An ERD is defined as “a graphical model that shows the logical model of the data for an organization (Dischiave, n.d.).” ERDs should follow the industry standard best practices in order to be most effective and useful overall. ERDs that do not follow certain best practices, which are outlined in this paper, could cause delays, inconsistencies, or lasting problems when designing and implementing a database. ERDs should follow set business rules, follow appropriate, effective and consistent naming conventions, should clearly outline unary, binary and ternary relationships, should include attributes, entities and relationships and should be clear and easy to follow (Hoffer, 2012). The article entitled