Module 5 Theory Questions

The purpose of a primary key is to assign each record in a table a unique identity. This ensures that each record can be uniquely identified and accessed, allowing for efficient data retrieval and manipulation. The primary key also enforces data integrity by preventing duplicate records from being entered into the table.

A primary key is used to assign a unique identity to a record in a database. It is a column or a combination of columns that uniquely identifies each record in a table. The primary key ensures that there are no duplicate records in the table and is used as a reference point for establishing relationships between tables. It is an essential component of database design and is used for data integrity and efficient data retrieval.

A database is a structured collection of records or data. It is a system used to organize and store large amounts of information in a way that allows for efficient retrieval and manipulation of data. By organizing data into tables and defining relationships between them, a database ensures data integrity and provides a reliable and efficient method for storing and accessing information.

A database administrator is responsible for providing users with access to the appropriate data. They manage and control the overall functioning of a database system, including granting permissions and setting up user accounts. They ensure that users have the necessary privileges to access and manipulate the data they need while also maintaining data security and integrity. A database architect is responsible for designing the overall structure and organization of a database system, while a database designer focuses on designing the specific tables, relationships, and attributes within the database. A database user is someone who interacts with the database to retrieve, input, or modify data.

Adding an index to a database allows for efficient searching and sorting of records. An index is a data structure that improves the speed of data retrieval operations by providing a quick lookup mechanism. It organizes the data in a specific order, allowing for faster searching and sorting based on the indexed field. Therefore, adding an index enables the database system to locate and retrieve the desired records more efficiently, resulting in improved performance when searching and sorting data.

The appropriate data type for a field containing decimal values is "Number". This data type allows for the storage of numeric values, including both whole numbers and decimal numbers. The AutoNumber data type is used for automatically generated unique identifiers, Text is used for storing text values, and Memo is used for storing large amounts of text.

In a table, each field should contain only one data element. This means that each field should hold a single value or piece of information. This ensures that the data in the table is organized and structured properly. Having only one data element per field allows for efficient data retrieval and manipulation, as well as maintaining the integrity and consistency of the table.

Relating tables in a database allows for the reduction of duplication of data. By establishing relationships between tables, data can be stored in a more organized and efficient manner. This means that instead of repeating the same data in multiple places, it can be stored in one table and referenced in other tables through the use of keys. This not only saves storage space but also ensures data integrity and consistency throughout the database.

Reducing the size of a field in a table can result in loss or corruption of data in the table because if the field size is decreased, it may not be able to accommodate all the data that was previously stored in it. This can lead to data being truncated or overwritten, resulting in loss or corruption of the data.

Relational integrity refers to the consistency and accuracy of data in a relational database. It ensures that relationships between tables are maintained and that data remains consistent across the database. In this context, relational integrity prevents adding a record to a related table when there is no associated record in the primary table. This ensures that the relationship between the two tables is maintained and that data remains accurate and consistent.