Implement Nested Loops Join

[xinyee20]

Changes in this PR

• Bug fix
• New feature
• Breaking change of an existing feature
• Refactor/Performance enhancements

Overview

Implementation of Nested Loops Join.

Test Command:

select sid, sname, eid from student, enroll where sid = studentid

Expected Result:

 sid sname eid
--------------
  1  joe 14
  1  joe 24
  2  amy 34
  4  sue 44
  4  sue 54
  6  kim 64

Output is correct.

To test sort-merge join for sorting that requires at least 2 runs

Test command: (requires 2 runs)

select sid,sname from student, enroll, section where sid=studentid and sectionid=sectid

Expected Result:

 sid sname
----------
  1  joe
  4  sue
  1  joe
  2  amy
  4  sue
  6  kim

Output is correct.

[don-tay]

Change optimization of join method to count based on num of block accesses:
with idx on sid:

SQL> select sid, sname, eid from student, enroll where sid = studentid
p1Cost: 19 p2Cost: 3 p3Cost: 13
Running sort merge
 sid sname eid
--------------
  1  joe 14
  1  joe 24
  2  amy 34
  4  sue 44
  4  sue 54
  6  kim 64

without idx on sid:

SQL> select sid, sname, eid from student, enroll where sid = studentid
p1Cost: 2147483647 p2Cost: 3 p3Cost: 13
Running sort merge
 sid sname eid
--------------
  1  joe 14
  1  joe 24
  2  amy 34
  4  sue 44
  4  sue 54
  6  kim 64

[xinyee20]

Change optimization of join method to count based on num of block accesses: with idx on sid:

SQL> select sid, sname, eid from student, enroll where sid = studentid
p1Cost: 19 p2Cost: 3 p3Cost: 13
Running sort merge
 sid sname eid
--------------
  1  joe 14
  1  joe 24
  2  amy 34
  4  sue 44
  4  sue 54
  6  kim 64

without idx on sid:

SQL> select sid, sname, eid from student, enroll where sid = studentid
p1Cost: 2147483647 p2Cost: 3 p3Cost: 13
Running sort merge
 sid sname eid
--------------
  1  joe 14
  1  joe 24
  2  amy 34
  4  sue 44
  4  sue 54
  6  kim 64

Context: p1 - IndexJoinPlan | p2 - MergeJoinPlan | p3 - NestedLoopsJoinPlan

[don-tay]

LGTM