Explain the difference between good and bad table structures. How do you recogni

Question

Explain the difference between good and bad table structures. How do you recognize the difference between good and bad structures? What role does normalization play in good and bad table structures, and why is normalization so important to a good table structure?

What is the importance of data validation? How can we avoid data-entry errors? How can forms help us reduce data-entry errors? What features does Access offer to help validate data? What are the different kinds of validations that are required?

Explanation / Answer

Explain the difference between good and bad table structures.

. Good tables having no redundant data.

. good tables can understand easily.

.good tables wont merge with many data

Bad table doesnt have proper structure

. bad table having more redundant data

bad table doesnt align properly

How do you recognize the difference between good and bad structures?

Bad table can easily identify by data redundancies.

Such redundancies produce update and delete anomalies that create data integrity problems. The loss of data integrity can destroy the usefulness of the data within the database.
Table structures are poor whenever they promote uncontrolled data redundancy

What role does normalization play in good and bad table structures, and why is normalization so important to a good table structure?

by using normalization we can avoid redundant data in good table

by using foreign key we can refer other table easily

bad table

More tables to join: By spreading out your data into more tables, you increase the need to join tables.
Tables contain codes instead of real data: Repeated data is stored as codes rather than meaningful data. Therefore, there is always a need to go to the lookup table for the value.
Data model is difficult to query against: The data model is optimized for applications, not for ad hoc querying.

good table

Smaller database: By eliminating duplicate data, you will be able to reduce the overall size of the database.
2. Better performance:
a. Narrow tables: Having more fine-tuned tables allows your tables to have less columns and allows you to fit more records per data page.
b. Fewer indexes per table mean faster maintenance tasks such as index rebuilds.
c. Only join tables that you need

What is the importance of data validation?

A validation check that can be applied to numeric fields is a range check, to ensure that only numbers within a certain range can be entered into a field.

A simple validation check can be used to to ensure that a particular value appears in this field only once, no matter how many records are in the database

How can we avoid data-entry errors?

we can allot id to all the fields

we can check manually all the data entry

How can forms help us reduce data-entry errors?

it having some order so we cant miss any data

What features does Access offer to help validate data?

Using the different data types available in Microsoft Access is one of the most simple forms of data validation. Access will not allow you to store the incorrect type of data in a field if the data type is not appropriate for the field's pre-defined data type.

What are the different kinds of validations that are required?

Using Validation Basic Operators

Usingv alidation with dates

using keyword validation

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