CISC 432/832

Assignment 2 – Block Nested Loops Join

Due Date: October 29, 2003.

This assignment is intended to give students an understanding of the issues involved in processing joins and handling files and buffer areas.

You are required to create and demonstrate a program that implements the block nested loops join algorithm described in Chapter 14 of the textbook. The program should be written in Java. Your implementation should include the following:

Buffer areas to hold the input and output relations and routines to manage the buffer areas. Remember it is more efficient to use blocks as the processing rather than records.
Routines to join blocks and move data between the buffer and files.
Creation of test files for your program. You may assume that the join fields are always integers.

Show that your program works for the cases when the small file fits into memory and when it does not. The block size and buffer area sizes should be parameters to your program.

Hand in listings of the source code for the program and all testing. You should also provide external documentation (3 - 5 pages) describing the design of your program, how to locate and use your program, your cost equations and the testing that you performed.

You must make your program files available to the TAs via the turnin program. Marks will be deducted for programs that do not run on the machines in the undergraduate lab.

A marking scheme for the assignment is available.

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School of Computing, Queen's University

CISC 432*/832*

Assignment 2 – Block Nested Loops Join

CISC 432/832