Basic Oracle Concepts and Programming Question:

If you have a table with a lots of rows, and you know that one of the columns will be used often a search criteria, you can add an index for that column to in improve the search performance. To add an index, you can use the CREATE INDEX statement as shown in the following script:

CREATE TABLE tip (id NUMBER(5) PRIMARY KEY,
subject VARCHAR(80) NOT NULL,
description VARCHAR(256) NOT NULL,
create_date DATE DEFAULT (sysdate));
Table created.

CREATE INDEX tip_subject ON tip(subject);
Index created.