what are materialised views in oracle?
155776
A materialized view is a database object that contains the results of a query. The FROM clause of the query can name tables, views, and other materialized views. ... In replication environments, the materialized views commonly created are primary key, rowid, object, and subquery materialized views.
565908
['An UNLOGGED table structure that can help in creating a backend LTT;', 'An automatic updatable VIEW with the name Global temporary table that will be used for the frontend SELECT/INSERT/DELETE/UPDATE; and.']
1287706
Views are used for security purposes because they provide encapsulation of the name of the table. Data is in the virtual table, not stored permanently. Views display only selected data. We can also use Sql Join s in the Select statement in deriving the data for the view.
1179898
['Views can represent a subset of the data contained in a table. ... ', 'Views can join and simplify multiple tables into a single virtual table.', 'Views can act as aggregated tables, where the database engine aggregates data (sum, average, etc.) ... ', 'Views can hide the complexity of data.']
174037
CDS Views. A view is an entity that is not persistent; it is defined as the projection of other entities. ... SAP HANA Extended Application Services (SAP HANA XS) enables you to define a view in a CDS document, which you store as design-time file in the repository.
468112
['Installing Oracle software.', 'Creating Oracle databases.', 'Performing upgrades of the database and software to new release levels.', 'Starting up and shutting down the database.', "Managing the database's storage structures.", 'Managing users and security.']
828787
A CDS view is defined for existing database tables and views, or for other CDS views in ABAP Dictionary, using the ABAP CDS statement DEFINE VIEW . A CDS view serves to define the structure of an SQL view and represents a projection onto one or several Dictionary tables or Dictionary views.
1093738
Django generic views are just view functions (regular old python functions) that do things that are very common in web applications. Depending on the type of app you are building, they can save you from writing a lot of very simple views.
1236202
The view is a query stored in the data dictionary, on which the user can query just like they do on tables. It does not use the physical memory, only the query is stored in the data dictionary.
157991
A view is a logical table that future queries can refer to. Views do not contain any data but it stores the query. ... Presto can access a Hive view only when its statement contains ANSI SQL dialects that Presto supports. Presto cannot access a Hive view when its statement contains non-ANSI SQL dialects.
1331511
A view can be defined as a virtual table or a stored query and the data accessible through a view is not stored in the database as a distinct object. Only the select statement is stored on the database instead. However, views can be used and perform DML operations ( Insert , Update & Delete ) also.
1101970
The falsehood is that Views are slower because the database has to calculate them BEFORE they are used to join to other tables and BEFORE the where clauses are applied. If there are a lot of tables in the View, then this process slows everything down.
53198
In SQL, a view is a virtual table based on the result-set of an SQL statement. A view contains rows and columns, just like a real table. The fields in a view are fields from one or more real tables in the database.
801379
A view is a virtual table because you can use it like a table in your SQL queries. ... To be precise, a view only behaves like a table. And it is just a named query stored in the database. When you query data from a view, Oracle uses this stored query to retrieve the data from the underlying tables.
866605
Unlike base tables, VIEW s are either updatable or read-only, but not both. INSERT , UPDATE , and DELETE operations are allowed on updatable VIEW s and base tables, subject to any other constraints.
183685
A materialized view is a database object that contains the results of a query. The FROM clause of the query can name tables, views, and other materialized views. Collectively these objects are called master tables (a replication term) or detail tables (a data warehousing term).
323598
A view is actually a composition of a table in the form of a predefined SQL query. A view can contain all rows of a table or select rows from a table. A MySQL view can be created from one or many tables which depend on the written MySQL query to create a view.