Oracle stores the definition of data along with the data. This data definition meant the data about the data i.e. Information about the users, table, columns, concerns, and all objects created in the database.
This information is stored in the form of a table which is called a data dictionary. The data dictionary is a read-only set of tables and is owned by SYS users. It is maintained by the oracle database server as an object structure available for the use of any user to query information about the database.
There are some commands to view the data which are given below
- DBA_USERS -> This stores the information of users.
- DBA_TABLES ->This stores the information about the table created by users.
- DBA_TAB_COLUMNS -> This stores the information about columns.
- DBA_CONSTRAINTS -> This stores the information about constraints.
- DBA_VIEWS -> This stores the information about views created by users.
- DBA_SEQUENCES -> This stores the information about sequences created by users.
- DBA _SYNONYMS -> This stores the information about synonyms created by users.
- DBA_MVIEWS -> This stores the information about materialized views created by users.