Briefly explain the architecture of the Oracle Database Management System

How is the SELECT and JOIN operation can be performed in a DBMS? Explain the Index Scan in the context of the SELECT operation. What is the cost of performing the SELECT operation using Index Scan? Also, write and explain the algorithms for performing a join using Nested-loop join and Block-nested loop join methods. Also, illustrate the computation of the cost of the join operations for Nested loop join with the help of an example.

Explain the concept of log-based recovery with the help of an example for the deferred database modification scheme. What is a checkpoint? How can it be used in recovery? Explain with the help of an example.

What are Multimedia databases? What are the challenges in designing multi-media databases? Also, explain the requirements of a Geographical Information System and features of Genome databases.

What is access control in the context of DBMS? What are the different access permissions that can be granted using SQL? Explain with the help of an example of each. Explain the concept of Statistical database security with the help of an example.

Create an XML document for Books using Book ID as an attribute. It should include information about the title of the Book, Author list of the Book, ISBN number of the book, Publisher of the Book, price of the book, year of publication and a brief description of the book. Create the necessary DTD to verify the document. You should show data of at least 3 books

Explain the following with the help of an example. 
(a) Stored Procedures and Triggers
(b) Embedded SQL

Explain the transaction management and indexing in PostgreSQL.