What is data dictionary views in PL SQL?

What is data dictionary views in PL SQL?

Data Dictionary is a read-only set of tables that provides information about the database. The definitions of all schema objects in the database (tables, views, indexes, clusters, synonyms, sequences, procedures, functions, packages, triggers). Informations about the schema objects. Default values for columns.

What are the types of views in PL SQL?

Types of Views in SQL | Views in SQL [2021]

• System Defined Views.
• Information Schema.
• Catalog View.
• Dynamic Management View.
• User Defined Views.
• Simple View.
• Complex View.

What are different types of views in Oracle?

There are 2 types of Views in SQL: Simple View and Complex View. Simple views can only contain a single base table. Complex views can be constructed on more than one base table. In particular, complex views can contain: join conditions, a group by clause, a order by clause.

What are data dictionary views in Oracle?

The USER, ALL, and DBA, views show information about schema objects that are accessible to you, at different levels of privilege. The V$ views show performance-related information. The _PRIVS views show privilege information for different combinations of users, roles, and objects.

What are the four types of views?

4.1: Types of views used in drawings

• perspective.
• isometric.
• oblique.

Who are the user of data dictionary?

Oracle accesses the data dictionary to find information about users, schema objects, and storage structures. Oracle modifies the data dictionary every time that a data definition language (DDL) statement is issued. Any Oracle user can use the data dictionary as a read-only reference for information about the database.

Where is the data dictionary stored in Oracle?

All data dictionary tables and views for a database are stored in the SYSTEM tablespace. Because the SYSTEM tablespace is always online when the database is open, the data dictionary is always available when the database is open. The Oracle Database user SYS owns all base tables and user-accessible views of the data dictionary.

How does Oracle create synonyms for data dictionary views?

Public Synonyms for Data Dictionary Views Oracle creates public synonyms for many data dictionary views so users can access them conveniently. The security administrator can also create additional public synonyms for schema objects that are used systemwide.

Where can I find the views of the data dictionary?

The views of the data dictionary serve as a reference for all database users. Access the data dictionary views with SQL statements. Some views are accessible to all Oracle users, and others are intended for database administrators only. The data dictionary is always available when the database is open.

What are the tables in the data dictionary?

All three views use the same list of data dictionary tables, except for the user$ table, which the USER_TABLES view does not use. The tables all three views use are: ts$, seg$, obj$, tab$, and obj$, which are all owned by sys.