If you drop a table, what happens to its indexes? The answer is that if a table is dropped, all its indexes will be dropped too. Try the following script to see yourself:

CREATE TABLE student (id NUMBER(5) PRIMARY KEY,

first_name VARCHAR(80) NOT NULL,

last_name VARCHAR(80) NOT NULL,

birth_date DATE NOT NULL,

social_number VARCHAR(80) UNIQUE NOT NULL);

Table created.

CREATE INDEX student_birth_date ON student(birth_date);

Index created.

SELECT index_name, table_name, uniqueness

FROM USER_INDEXES WHERE table_name = 'STUDENT';

INDEX_NAME   TABLE_NAME  UNIQUENES

----------------------- --------------------- ---------

SYS_C004141   STUDENT   UNIQUE

SYS_C004142   STUDENT   UNIQUE

STUDENT_BIRTH_DATE STUDENT   NONUNIQUE

DROP TABLE STUDENT;

Table dropped.

SELECT index_name, table_name, uniqueness

FROM USER_INDEXES WHERE table_name = 'STUDENT';

no data found

No records in USER_INDEXES view found for your name STUDENT, after you dropped STUDENT table.