What is a materialized look?

Material display is a database object in which the information required from the database is displayed. The database is a collection of information arranged in the table format. It allows the end user to load the data via queries located in a structured language format (SQL) format. This allows the end user to submit applications from the database for specific types of information, such as a list of employees under 30 years. This information would be accessible in a materialized view, providing a specific virtual table that contains a complete list of results. It compares the required information with each individual record in selected tables. So, continuing the previous example, in search of employees under 30 years, the database goes to the "employee" table and from the very beginning examines the date of birth of everyone and compares it to the sactual date that comes with age. All employees under 30 years are moved to a table of materialized display. Only then is the final material handed over to “Submittingthe end of the end user and provides a complete answer to the desired question.

In contrast to the traditional view of the relational database, which stores questions in the temporary table, it stores the materialized view of the interviewed information in the actual, permanent, specific tables. The information stored in the materialized view is stored in the cache in the system memory, allowing the end user to make changes or update data from time to time. For example, if the same example of the query - all employees under 30 - is done on the first day, it remains in the system as a materialized view from now on.

The advantage is that information re -approaches is much faster; The information is already stored in the system. The aprime disadvantage is that the information can be outdated or expired between the time of access. For example, if the end user re -receives the same materialized driveLED in ten day, it could change: someone could just turn 30. The version of the Materized View will not take into account until the whole query is re -launched.