Moreover, it is likely that the business requirements are already defined, the scope of your application has been agreed upon, and you have a conceptual design.
Feedback documentation by users. The diagrams produced should show the processes and data that exists, as well as the relationships between business processes and data. Choose Type of service. One output of the logical design is a set of entities and attributes corresponding to fact tables and dimension tables.
This is necessary in order to gather all requirements of the database accurately and completely. It is reviewed by developers, management, and finally the end users to see if more information needs to be gathered before physical modeling starts.
End users typically want to perform analysis and look at aggregated data, rather than at individual transactions. It is software specific. Set up the table relationships - Look at each table and decide how the data in one table is related to the data in other tables.
At the end of the system design phase, documentation describing the three sub-tasks is produced and made available for use in the next phase. Logical database modeling includes; ERD, business process diagrams, and user feedback documentation; whereas physical database modeling includes; server model diagram, database design documentation, and user feedback documentation.
There are two data models, logical and physical.
Physical Database Model Physical database modeling deals with designing the actual database based on the requirements gathered during logical database modeling.
Physical modeling deals with the conversion of the logical, or business model, into a relational database model. Database normalization In the field of relational database design, normalization is a systematic way of ensuring that a database structure is suitable for general-purpose querying and free of certain undesirable characteristics—insertion, update, and deletion anomalies that could lead to loss of data integrity.
Processing requirements, System control and backup or recovery. Physical If you are reading this guide, it is likely that your organization has already decided to build a data warehouse.
All the information gathered is converted into relational models and business models. A Ring topology would be: Business process diagram—It shows the activities of individuals within the company.
A good logical design will have the foundation for security which provides the framework stages needed for security. The elements that help you to determine the data warehouse schema are the model of your source data and your user requirements.
The physical implementation of the logical data warehouse model may require some changes due to your system parameters--size of machine, number of users, storage capacity, type of network, and software. However, some modeling disciplines, such as the dimensional modeling approach to data warehouse design, explicitly recommend non-normalized designs, i.
The basic idea behind the physical design is to communicate what hardware should be used in the network.Jul 22, · Logical and physical database models are required in order to visually present the database that has been proposed for a certain business requirement. The models help in showing the association of business requirements and the database objects.5/5(1).
By having a logical model of a data base (objects), we can determine a suitable physical design of the data base. It is the failure to prepare such logical designs that inevitably leads to problems in physical design later on, particularly when it is necessary to prove that a physical solution solves a logical design (aka, "Design Correctness").
Data Modeling Data Warehousing > Concepts > Data Modeling - Conceptual, Logical, And Physical Data Models The three levels of data modeling, conceptual data model, logical data model, and physical data model, were discussed in prior sections.
In a sense, logical design is what you draw with a pencil before building your warehouse and physical design is when you create the database with SQL statements.
During the physical design process, you convert the data gathered during the logical design phase into a description of the physical. The physical design of the network is derived from the logical design and the physical design will often expand on the elements found in the logical design.
For example, let’s say that the logical design shows a WAN connection as line between to buildings. 2 Overview of Logical Design.
This chapter tells how to design a data warehousing environment, and includes the following topics: Logical vs. Physical.Download