Any database has its main constituents in a table. The concept of Views arises when you want to access data from the table. In simple words, using Views, a user can selectively access only the required data instead of viewing the overall content present in it. Now, based on the overall features and characteristics, there are two types of views. In this article, we will look into the difference between Views and Materialistic views in SQL.
What are Views in SQL?
These are virtual tables created by the command- Create View. The Views consist of retrieved data out of a query expression using the Create View command. One can easily create views out of one or more such base tables or multiple views. Also, you can query a View like that of the original base tables that constitute it.
What are Materialized Views in SQL?
It is actually the physical copy of the primary base tables (original ones). A Materialized View is more like a picture or a snapshot of the original base tables that make up the virtual tables. Just like Views, the Materialized Views also consist of the data and information retrieved out of the query expression using the command of Create Materialized View.
Difference Between Views and Materialized Views in SQL
Here is a list of the differences between Views and Materialized Views in SQL.
| Parameters | Views in SQL | Materialized Views in SQL |
| Meaning and Definition | A View is technically a virtual logical copy of the table formed by the select query. Here, the result doesn’t get stored in the disk, and whenever we need the data, we also need to fire the query. This way, we can get updated with the latest data and information from the original tables. | The Materialized Views are also virtual logical copies to the data and information of the select query. But it stores the result of the query in the disk or the table. |
| Storage | It does not store the tuples resulting from the query expression on the disk. It only allows the storage of query expressions on any disk. | Materialistic Views allow the storage of both on their disk- tuples resulting from queries and the query expression. |
| Execution of Queries | The Views allow the storage of query expressions on the disk. But the result of these queries does not get stored on the disk. Thus, there is an execution of the query expression every time a user fetches data. This way, the user gets a piece of updated information or the latest data every time they fetch it. | The Materialized Views store the result of the queries on the disk along with the query expression. This way, execution of the query expression does not always occur whenever a user tries to fetch a piece of information or data. As a result, the user won’t get updated information or the latest updated data from the database, even if there are some changes. |
| Cost-Effective | Views do not come with a cost of storage. Thus, they also don’t have the cost of updates. Thus, it is more efficient with the cost. | On the other hand, Materialized Views come with a storage cost along with a cost for further updates. Thus, it is comparatively less efficient with the cost. |
| Design | The Views in SQL have a fixed approach to architecture. Thus, there is an SQL standard that defines a view. | The Materialized Views in SQL have a generic approach to architecture. Thus, there exists no SQL standard that defines it. The functionalities of Materialized Views are provided in the form of extensions from some of the DBS (database systems). |
| Uses | We generally make use of the Views when we need to access data infrequently while the data contained in the table gets updated and altered on a regular basis. | We generally make use of the Materialized Views when we access data frequently- but the overall information in the database does not have any frequent updates and stays quite the same for a majority of the time. |
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