Contents
How do you redesign a database?
The design process consists of the following steps:
- Determine the purpose of your database.
- Find and organize the information required.
- Divide the information into tables.
- Turn information items into columns.
- Specify primary keys.
- Set up the table relationships.
- Refine your design.
- Apply the normalization rules.
Why do databases need redesigning?
Database redesign is required to adapt the database to do some changes in system requirements. When the new system is installed in the database, then new information system is to be required to be redesign in the database. As the user needs some new requirements, then the systems should be changed by the users needs.
Why do we say a database is self describing and why is this an advantage?
A database is considered self-describing because it contains a description of its own structure within the database itself. The advantage is that the database is self-documenting, and that a knowledgeable user or a database designer can easily access the metadata.
What is data inconsistency in DBMS?
Data inconsistency is a situation where there are multiple tables within a database that deal with the same data but may receive it from different inputs. Inconsistency is generally compounded by data redundancy.
Why do we use view?
Simplicity for queries and structure: A view can draw data from several tables and present a single table, simplifying the information and turning multi-table queries into single-table queries for a view and it give users a specific view of the database structure, presenting the database as a set of virtual tables …
Why do we say a database is self-describing?
A database system is referred to as self-describing because it not only contains the database itself, but also metadata which defines and describes the data and relationships between tables in the database. This information is used by the DBMS software or database users if needed.
What’s the best way to redesign a database?
Create a good solid set of test cases so that you can compare that results with the old system are the same with the new system. Because you have so many years of data you may want to migrate in two parts. First migrate most of the data and then when it is time to go live, only migrate changed data.
What makes a good design for a database?
Database design is usually dictated by how you’re using your data today and how your organization plans to use it in the future. If you already have a database with existing data, then you have to consider how you’ll migrate as well. For every database use case, there are different types of databases, database software, and specific designs.
Why do people take shortcuts in database design?
While they are often under pressure to deliver a database in a relatively short period of time, Cave said taking design shortcuts to help meet a deadline can make it much tougher to add new functionality in the future. “If you properly design a database upfront, it is going to work for everybody.
Do you forego data models in database design?
Despite widespread agreement that software engineering is important, many programmers forego data models in database design, said Michael Blaha, a partner at Modelsoft Consulting and author of seven books including “Object-Oriented Modeling and Design.”