Introduction

In this assignment, you will implement the index nested loops join algorithm. You will carry out this assignment in teams with the same partner(s) as in previous assignments.

Available Documentation

You should begin by reading the chapter on Implementation of Relational Operations, in particular, the section on Index Nested Loops Join.

What You Have to Implement

class index_nested_loop {
  public:

    index_nested_loop(
      char     *filename1,    // Name of heapfile for relation R.
      int       len_in1,      // # of columns in R.
      AttrType  in1[],        // Array containing field types of R.
      short     t1_str_sizes[], // Array containing size of columns in R.
      int       join_col_in1,   // The join column number of R.
      char     *filename2,    // Name of heapfile for relation S
      int       len_in2,      // # of columns in S.
      AttrType  in2[],        // Array containing field types of S.
      short     t2_str_sizes[], // Array containing size of columns in S.
      int       join_col_in2, // The join column number of S.
      char     *filename3,    // Name of heapfile for joined results
      IndexType intype,       // Index type
      Status&   s             // Status of constructor
    );
   ~index_nested_loop() {}
};

The index_nested_loop constructor joins two relations R and S, represented by the heapfiles filename1 and filename2, respectively, using the index nested loops join algorithm. Note that the columns for relation R (S) are numbered from 0 to len_in1 - 1 (len_in2 - 1). You are to concatenate each matching pair of records and write it into the heapfile filename3. The error layer for the index_nested_loop class is JOINS.

You will need to use the following classes which are given: HeapFile, Scan, BTreeFile and BTreeFileScan. You will call BTreeFile methods to build up a btree index for the inner heapfile S. Then you scan the outer heapfile R, for each tuple in the outer heapfile R, retrieve the matching S tuples by scaning the Btree index on the inner heapfile S.

Where to Find Makefiles, Code, etc.

The structure files for the classes you will be using can be found in the directory:

	/usr/local/minibase/minibase-2.0/include

You will need to copy files from the src directory for this assignment. To do this you need to follow the same steps as in assignments 1 and 2:

1. Make an appropriate directory to work in.
2. Copy the file Makefile from the directory

   		/usr/local/minibase/mini_hwk/assign/INL_Join/src
          

3. Execute the call:

   		make setup
          

   which will copy the appropriate files.
4. Implement the assignment -- you can type make to attempt to compile your solution.

The files you copy are:

• Makefile: A sample makefile to compile your project.
• index_nl.h: Specifications for the class index_nested_loop. You have to implement these specifications as part of the assignment.
• index_nl_driver.C: index nested loop join test driver program.
• index_nl.C: A skeleton of the routine you need to complete.

What to Turn In, and When

You should turn in copies of your code together with copies of the output produced by running the tests provided.