Difference Between Materialized View And View In Database

What Is Materialized View?

In computing, a materialized view is a database object that contains the results of a query. For example, it may be a local copy of data located remotely or may be a subset of the rows and or columns of a table or join result or may be a summary using an aggregate function.

Materialized views can be used for many purposes, including:

• Denormalization
• Validation
• Data Warehousing
• Replication

What You Need To Know About Materialized View

• Materialized views are physical copies of origin tables contained by a database.
• Materialized views are non-virtual schema. It is a common part of database warehousing. It is primarily used for summarizing, pre-computing, replicating and distributing data etc.
• A materialized view is capable of storing data. It makes accessibility to data a faster process.
• Materialized views have to be updated with the use of triggers or manually.
• Materialized views are stored on the disc.
• A materialized view is capable of being stored in a different database or the same database as the base table (s).
• There is no SQL standard for defining a materialized view and the functionality is provided by some database systems as an extension.
• The rowid is different in case of materialized views.
• A materialized view is fast in processing. A materialized view log serves as a schema object that records all changes on to the data contained in a master table and can be refreshed incrementally.
• A materialized view does not reflect real-time data. The data is only as up to date as the last time the materialized view was refreshed.
• A materialized view is best utilized when you have a really big table and people do frequent aggregates on it and you require fast response.
• A materialized view is a ‘’pre-answered’’ query- the query is executed when the materialized view is refreshed. Its result is stored in the database and the query only browses the result.
• DML commands are capable of being made in materialized views.
• Materialized views are efficient when the view is accessed frequently.

View

Views in database are kind of logical virtual tables.  It is actually a composition of a table in the form of a predetermined SQL query. A view also has rows and columns as they are in real table in the database. We can create a view by selecting fields from one or more tables present in the database which depends on the written SQL query to create a view. A view can either have all the rows of a table or specific rows based on certain conditions.

Views, which are a type of virtual tables, allow users to do the following:

• Structure data in a way that users or classes of users find natural or intuitive.
• Restrict access to the data in such a way that a user can see and sometimes modify exactly what they need and no more.
• Summarize data from various tables which can be used to generate reports.

What You Need To Know About View

• Views are virtual tables that are developed from a single/multiple views or tables.
• Views are the virtual projections of an output query or the dynamic view of data in a database that is presented to the user whenever requested.
• Views are not capable of storing any data, they only point to the data that has to be viewed.
• Views are automatically updated every time a virtual view/table is put to use.
• Views are not stored physically on the disk.
• A view is capable of being used in the places wherever a table can be put to use.
• There is an SQL standard of defining a view.
• When a view is created with the use of any table, then the rowed of the view will be same as the rowed of the original table.
• Views are slow to process.
• A view’s output is built on the fly; it shows real-time data from the base tables being queried.
• A view is best utilized when you want to hide the implementation details of a complex query or when you want to restrict access to a set of rows/columns in the base tables.
• A view’s SQL is executed at run-time. The results are fetched from the view’s base tables when the view is queried.
• In simple views, DML commands are not a possibility in case they are made using multiple tables.
• Views are useful when the view is accessed infrequently.

Also Read: Difference Between Normalization And Denormalization In SQL

Difference Between Materialized View And View In Tabular Form

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