DUAL TABLE IN ORACLE

In oracle dual is a predefined virtual table which contains only one row and one column. This table is available in SYS user. We cannot perform DML operations in Dual table. Dual table can be accessed by all users in Oracle database. Generally dual table is used to test predefined, user-defined functions functionality.

To view dual table

SQL> select * from dual;

By default dual table column data-type is varchar