The main difference between view and materialized view is that view is a virtual table that is not stored in the disk while materialized view is a physical copy of the original database that is stored in the disk.
DBMS is a software that allows storing and managing data in databases. A Relational DBMS (RDBMS) is a DBMS that is designed according to the relational model. Programmers can write SQL queries to perform operations on an RDBMS. An RDBMS has databases, and each database consist of one or more tables. In addition to databases and tables, there are various other concepts. Two of them are view and materialized view.
Key Areas Covered
1. What is View
-Definition, Functionality
2. What is Materialized View
-Definition, Functionality
3. Difference Between View and Materialized View
-Comparison of key differences
Key Terms
View, Materialized View, RDBMS
What is View
The view is a logical subset of data from one or more tables. It helps to restrict access to data. Moreover, a view contains data obtained from a query expression. The programmer can write the SQL queries to create update and delete views. He can write queries similar to the tables. It is also possible to create a customized view of a complex database.
Unlike a regular table, view is not pre-computed and stored on the disk. When updating the view, it displays the changes made to the original table. Generally, the performance of a view is lower. It is because a view requires joining two or more tables. Therefore, the view takes more time as it requires time to process the joins. Moreover, a view with one table is a simple view, while a view with more tables is a complex view.
The main advantage of view is that it does not require much storage space. Therefore, if the user needs getting an overview of records from multiple tables, he can create a view and check the data. It helps to restrict the user from access to confidential data. Furthermore, it minimizes the complexity of the queries by connecting multiple tables to generate a single view.
What is Materialized View
A materialized view is the physical copy of the original tables. It is similar to a snapshot or picture of the original tables. Similar to a view, it contains data as described in the query expression. Furthermore, a materialized view is stored on the disk.
Materialized view does not get updated each time. However, the programmer can update it manually or by using a trigger. Furthermore, a materialized view is pre-computed. Thus, it does not require time to process the query or joins. Therefore, a materialized view is faster.
Difference Between View and Materialized View
Definition
A view is a database object that allows generating a logical subset of data from one or more tables. In contrast, a materialized view is a physical copy of the original database that is stored in the disk. Thus, this is the main difference between view and materialized view.
Storing
Moreover, the view is not stored in the disk, while the materialized view is stored in the disk. Therefore, the view does not require memory.
Execution Speed
Another difference between view and materialized view is that view is slower than materialized view.
Update
It is necessary to update the view each time using it. On the other hand, it is not necessary to update the materialized view each time using it.
Conclusion
View and materialized view are two concepts related to RDBMS. The main difference between view and materialized view is that view is a virtual table that does not store in the disk while materialized view is a physical copy of the original database that is stored in the disk.
References:
1.“SQL VIEW.” Studytonight, Available here.
2.“Materialized View.” Wikipedia, Wikimedia Foundation, 26 Mar. 2019, Available here.
Image Courtesy:
1.”1895779″ via Pixabay
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