oracle information_schema

The "information_schema" is a schema in Oracle that provides information about the database objects. It contains a set of views that can be queried to retrieve metadata information about tables, views, columns, indexes, constraints, and other database objects.

Some of the commonly used views in the information_schema schema are:

• TABLES: This view provides information about tables in the database, such as table name, schema name, and table type (base table, view, or system table).
• COLUMNS: This view contains information about columns in the database tables, including column name, data type, length, and nullability.
• VIEWS: This view lists all the views in the database, providing information about the view name, schema name, and view definition.
• INDEXES: This view provides information about indexes defined on tables, including index name, table name, column name, and index type.
• CONSTRAINTS: This view contains information about constraints defined on tables, such as primary key, foreign key, unique key, and check constraints.

These views can be queried to retrieve information about the database schema, which can be useful for various purposes, such as database administration, data analysis, and application development