How do I view data dictionary in SQL?
How do I view data dictionary in SQL?
You can do this by using the INFORMATION_SCHEMA. COLUMNS view. & For instance, the following lists all tables and views containing the column BusinessEntityID . As you can imagine, the data dictionary can come in handy!
What is the data dictionary view for view?
Data dictionary views may be grouped into four general categories: Those showing data about a user’s own objects, labeled “USER_” Those showing data available to any user in the database, labeled “ALL_”
How is a view stored in the data dictionary?
The data dictionary is structured in tables and views, just like other database data. All the data dictionary tables and views for a given database are stored in that database’s SYSTEM tablespace. Because the data dictionary is read only, you can issue only queries ( SELECT statements) against it’s tables and views.
What is the difference between table and view in SQL?
A view is a virtual table. A view consists of rows and columns just like a table. The difference between a view and a table is that views are definitions built on top of other tables (or views), and do not hold data themselves. If data is changing in the underlying table, the same change is reflected in the view.
What is data dictionary SQL?
The SQL Server data dictionary stores information about a database’s definition. The dictionary contains information about database objects such as tables, indexes, columns, datatypes, and views.
What is the use of data dictionary in Oracle?
Oracle Data Dictionary. The Oracle data dictionary is one of the most important components of the Oracle DBMS. It contains all information about the structures and objects of the database such as • tables, • columns, • users, • data files etc. The data stored in the data dictionary are also often called metadata.
What are data dictionary views?
Those showing data about a user’s own objects,labeled “USER_”
What are the elements of a data dictionary?
Data dictionary elements. A data dictionary is composed of data dictionary elements (DDEs) of which there are three types: Simple, Composite, and Collection elements. Simple DDEs are primitive elements such as strings, numbers, dates, and Boolean values that hold information such as a city name.
What is Oracle Database View?
A view is a named and validated SQL query which is stored in the Oracle data dictionary . Views do not contain any data – it is just a stored query in the database that can be executed when called. One can think of a view as a virtual table or mapping of data from one or more tables.
