Difference Between View and Table

Definition and Functionality of Tables

Tables are database objects that store data in a structured manner. A table consists of a collection of rows and columns, with each column representing a specific attribute of the data and each row representing a unique instance of the data. Tables are used to store and manage large amounts of data in a relational database system, and they are designed to ensure data consistency, data integrity, and data security.

The primary purpose of a table is to provide a way to organize data in a logical and structured format and to allow users to perform various operations on the data, such as inserting, updating, deleting, and querying data. Tables can be queried using SQL commands, which enable users to retrieve specific subsets of data from the table based on certain criteria.

Tables provide several key functionalities, including:

1. Data storage: Tables provide a structured and organized way to store data, which makes it easier to manage and maintain large amounts of data.
2. Data manipulation: Tables allow users to perform various operations on the data, such as adding new rows or modifying existing rows.
3. Data retrieval: Tables can be queried using SQL commands to retrieve specific subsets of data based on certain criteria.
4. Data integrity: Tables enforce rules and constraints that ensure data consistency and integrity, such as primary keys, foreign keys, and unique constraints.
5. Data security: Tables provide a way to control access to sensitive data by setting up permissions and privileges for different users or user groups.

Definition and Functionality of Views

Views are database objects that provide a way to retrieve and present data from one or more tables in a relational database system. A view is a virtual table that does not actually store data itself, but rather provides a way to access data stored in underlying tables. Views are used to simplify complex queries, reduce data redundancy, and provide an additional level of security by controlling access to sensitive data.

The primary purpose of a view is to provide a logical representation of data stored in one or more tables, without actually changing the underlying data. Views can be thought of as virtual tables that are defined by SQL queries, and they can be queried just like regular tables. Views can combine data from multiple tables, apply filters or sorting, and perform calculations or other operations on the data.

Views provide several key functionalities, including:

1. Data retrieval: Views provide a way to retrieve specific subsets of data from one or more tables based on certain criteria, which can simplify complex queries and improve query performance.
2. Data filtering: Views can be used to filter out unwanted data or restrict access to sensitive data by defining SQL queries that limit the data displayed in the view.
3. Data aggregation: Views can perform calculations or other operations on the data, such as summing, averaging, or grouping data, which can simplify complex queries.
4. Data security: Views can provide an additional layer of security by controlling access to sensitive data stored in underlying tables, without granting direct access to the tables themselves.
5. Data abstraction: Views can provide a way to present data to users in a more user-friendly or understandable way, by hiding the underlying complexity of the data model or database schema.

 Differences between View and Table

There are several key differences between tables and views in a relational database system, including:

1. Data storage: Tables store actual data, while views store queries that retrieve data from one or more tables. Tables are used to store and manage large amounts of data, while views provide a way to access and manipulate data stored in tables.
2. Data manipulation: Tables can be used to perform various operations on the data, such as inserting, updating, deleting, and querying data. Views, on the other hand, are read-only and cannot be used to modify the underlying data. Instead, views are used to retrieve data based on specific criteria or to present data in a more user-friendly format.
3. Data redundancy: Tables can sometimes contain redundant data, which can lead to data inconsistencies or inefficiencies. Views, on the other hand, can be used to reduce data redundancy by combining data from multiple tables into a single view.
4. Data security: Tables can be accessed directly by users, which can pose a security risk if sensitive data is stored in the table. Views provide an additional layer of security by controlling access to sensitive data stored in underlying tables, without granting direct access to the tables themselves.
5. Query complexity: Tables can sometimes be difficult to query if they contain large amounts of data or if the data is spread across multiple tables. Views can simplify complex queries by combining data from multiple tables, applying filters or sorting, and performing calculations or other operations on the data.
6. Performance: Tables generally provide better performance for operations that involve inserting, updating, or deleting large amounts of data. Views are generally better for querying and analyzing data, especially if the view combines data from multiple tables or applies complex filters or calculations.

Tables and views serve different purposes in a relational database system and should be used in different ways depending on the specific needs of the application or use case.

Advantages and Disadvantages of View and Table

Advantages of Tables:

1. Efficient data storage: Tables provide an efficient way to store and manage large amounts of data in a structured and organized manner.
2. Data integrity: Tables enforce rules and constraints that ensure data consistency and integrity, such as primary keys, foreign keys, and unique constraints.
3. Data manipulation: Tables allow users to perform various operations on the data, such as inserting, updating, deleting, and querying data.
4. High performance: Tables generally provide better performance for operations that involve inserting, updating, or deleting large amounts of data.

Disadvantages of Tables:

1. Data redundancy: Tables can sometimes contain redundant data, which can lead to data inconsistencies or inefficiencies.
2. Query complexity: Tables can sometimes be difficult to query if they contain large amounts of data or if the data is spread across multiple tables.
3. Security risks: Tables can be accessed directly by users, which can pose a security risk if sensitive data is stored in the table.

Advantages of Views:

1. Data abstraction: Views can provide a way to present data to users in a more user-friendly or understandable way, by hiding the underlying complexity of the data model or database schema.
2. Simplified queries: Views can simplify complex queries by combining data from multiple tables, applying filters or sorting, and performing calculations or other operations on the data.
3. Improved security: Views provide an additional layer of security by controlling access to sensitive data stored in underlying tables, without granting direct access to the tables themselves.
4. Reduced data redundancy: Views can be used to reduce data redundancy by combining data from multiple tables into a single view.

Disadvantages of Views:

1. Performance overhead: Views can sometimes incur a performance overhead, especially if the view combines data from multiple tables or applies complex filters or calculations.
2. Limited data manipulation: Views are read-only and cannot be used to modify the underlying data. Instead, views are used to retrieve data based on specific criteria or to present data in a more user-friendly format.
3. Query limitations: Views have certain limitations on the types of queries that can be performed, such as limitations on the use of aggregate functions or the ability to perform complex calculations.

Tables and views both have their own advantages and disadvantages, and their use should be based on the specific needs of the application or use case. Tables are generally better for storing and manipulating large amounts of data, while views are better for presenting data in a more user-friendly way and controlling access to sensitive data.

Examples of When to Use Tables versus Views

Here are some examples of when to use tables versus views:

1. Use tables when you need to store and manage large amounts of data that needs to be manipulated frequently, such as customer orders or employee data.
2. Use views when you need to present data to users in a more user-friendly way, such as combining data from multiple tables into a single view or filtering data based on specific criteria.
3. Use tables when you need to perform complex data manipulations such as aggregations, sorting, or grouping, as these operations are generally faster and more efficient when performed directly on the table.
4. Use views when you need to enforce data security and limit access to sensitive data stored in underlying tables.
5. Use tables when you need to perform insert, update, or delete operations on the data, as views are read-only and cannot be used to modify the underlying data.
6. Use views when you need to simplify complex queries by combining data from multiple tables, applying filters or sorting, and performing calculations or other operations on the data.

For example, if you have a database that stores customer orders, you would use a table to store the customer order data, and you would use views to present the order data to users in a more user-friendly way, such as by combining data from multiple tables into a single view, or filtering data based on specific criteria such as the order date or product type. Similarly, if you have a database that stores employee data, you would use a table to store the employee data, and you would use views to present the employee data to users in a more user-friendly way, such as by grouping data by department or filtering data based on job title.

Conclusion

Tables and views are both essential components of relational databases, with distinct advantages and disadvantages. Tables provide an efficient way to store and manipulate large amounts of data, enforce data integrity, and perform complex data manipulations.

Views, on the other hand, provide a way to present data to users in a more user-friendly way, simplify complex queries, and enforce data security. The choice of whether to use a table or a view depends on the specific needs of the application or use case, and both tables and views can be used in combination to create effective and efficient database designs.

References Website

1. Oracle – Tables: https://docs.oracle.com/en/database/oracle/oracle-database/19/sqlrf/CREATE-TABLE.html
2. Oracle – Views: https://docs.oracle.com/en/database/oracle/oracle-database/19/sqlrf/CREATE-VIEW.html
3. MySQL – Tables: https://dev.mysql.com/doc/refman/8.0/en/creating-tables.html
4. MySQL – Views: https://dev.mysql.com/doc/refman/8.0/en/create-view.html
5. SQL Server – Tables: https://docs.microsoft.com/en-us/sql/relational-databases/tables/create-tables-basic-syntax
6. SQL Server – Views: https://docs.microsoft.com/en-us/sql/relational-databases/views/create-views-transact-sql
7. W3Schools – SQL Tables: https://www.w3schools.com/sql/sql_create_table.asp
8. W3Schools – SQL Views: https://www.w3schools.com/sql/sql_view.asp