Question 1 :
Indexes are created to enforce uniqueness on columns and to enable fast retrieval by column values.
Question 2 :
Money is defined in Oracle with the Currency data type.
Question 3 :
The default extension for SQL*Plus is .sql.
Question 4 :
The left-leaning slash tells Oracle to execute whatever statement is in the buffer.
Question 5 :
Oracle maintains a System Change Number (SCN) which is a database-wide value that is incremented by Oracle whenever database changes are made.