[TAJO-741] GreedyHeuristicJoinOrderAlgorithm removes some join pairs.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.8.0, 0.9.0
• Fix Version/s: 0.8.0, 0.9.0
• Component/s: distributed query plan, Planner/Optimizer
• Assignee: JaeHwa Jung
• Reporter: JaeHwa Jung
• Created: 08/Apr/14 02:57
• Updated: 21/Apr/14 06:38
• Resolved: 18/Apr/14 08:06

Description

I found a bug for GreedyHeuristicJoinOrderAlgorithm as follows:

1. Table Schema

create external table table1 (id int, name text, score float, type text) using csv with ('csvfile.delimiter'='|') location 'hdfs://server01:9010/tajo/warehouse/table1' ;

create external table table3 (id int, name text, score float, type text) using csv with ('csvfile.delimiter'='|') location 'hdfs://localhost:9010/tajo/warehouse/table3' ;

create external table table4 (id int, name text, score float, type text) using csv with ('csvfile.delimiter'='|') location 'hdfs://localhost:9010/tajo/warehouse/table4' ;

2. Table Data

2.1 table1
1|name1-1|1.1|a
2|name1-2|2.3|b
3|name1-3|3.4|c
4|name1-4|4.5|d
5|name1-5|5.6|e

2.2 table3
1|name3-1|0.1|a
2|name3-2|0.2|b
3|name3-3|0.3|b

2.3 table4
1|name4-1|22.3|a
2|name4-2|23.4|b
3|name4-3|24.5|cc
5|name4-4|25.6|ee
6|name4-5|31.1|ff
7|name4-6|32.3|gg

3. Query

select a.name, c.name, a.type, c.type from table1 a join table3 b on (a.id = b.id) join table4 c on (b.id = c.id) where a.type =  c.type;

4. Expected Result

name,  name,  type,  type
-------------------------------
name1-1,  name4-1,  a,  a
name1-2,  name4-2,  b,  b

5. Actual Result

name,  name,  type,  type
-------------------------------
name1-1,  name4-1,  a,  a
name1-2,  name4-2,  b,  b
name1-3,  name4-3,  c,  cc

I found that default.a.type (TEXT) = default.c.type (TEXT) is in initiative plan result and FPD result.
But after executing GreedyHeuristicJoinOrderAlgorithm, it disappeared in logical plan.

Issue Links

• relates to: TAJO-636 The number of TPC-H 10 query results are wrong.
• relates to: TAJO-727 TPC-DS Q32 returns no result.