[HIVE-5552] Merging of QBJoinTrees doesn't handle filter pushdowns correctly

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.13.0
• Component/s: Query Processor
• Assignee: Harish Butani
• Reporter: Harish Butani
• Created: 15/Oct/13 23:31
• Updated: 27/Oct/13 09:19
• Resolved: 25/Oct/13 20:46

Description

The following query fails:
(this based on the schema from auto_join_filters.q)

explain
SELECT sum(hash(a.key,a.value,b.key,b.value)) 
FROM myinput1 a LEFT OUTER JOIN myinput1 b on a.value = b.value  RIGHT OUTER JOIN myinput1 c 
     ON 
        b.value = c.value AND 
        a.key > 40

Whereas this query succeeds

explain
SELECT sum(hash(a.key,a.value,b.key,b.value)) 
FROM myinput1 a LEFT OUTER JOIN myinput1 b RIGHT OUTER JOIN myinput1 c 
     ON  a.value = b.value and
        b.value = c.value AND 
        a.key > 40

Pushing the first condition to the first join, triggers a merge of the 2 QBJoinTrees. During merge all the right side filters identified for pushing are assumed to refer to the merging table (b in this case). But the pushable filters can refer to any left table.

Issue Links

• is depended upon by: HIVE-5555 Support alternate join syntax: joining conditions in where clause; also pushdown qualifying join conditions