[CALCITE-2296] Extra logic to derive additional filters in the FilterJoinRule

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.16.0
• Component/s: core
• Assignee: Unassigned
• Reporter: Vitalii Diravka
• Created: 02/May/18 12:24
• Updated: 18/Jun/21 08:31

Description

There is necessary to add logic to derive additional filters from for FilterJoinRule in the case of using disjunction of expressions:
https://github.com/apache/calcite/blob/master/core/src/main/java/org/apache/calcite/rel/rules/FilterJoinRule.java#L155

The example query is:

 
select * from sales.emp e join 
sales.dept d on e.job = d.name
where (e.deptno = 5 AND d.deptno = 2)
OR (e.deptno = 7 AND d.deptno = 3)

The filrer condition in DNF
LogicalFilter(condition=[OR(AND(=($7, 5), =($9, 2)), AND(=($7, 7), =($9, 3)))])
can be transformed into CNF and then the ncessary filters can be pushed down:
LogicalFilter(condition=[OR(=($7, 5), =($7, 7))]) and LogicalFilter(condition=[OR(=($9, 2), =($9, 3))])
Additional filter still will be present on top of join.

Finally deriving additional filters can allow to scan less information.

Issue Links

• is required by: DRILL-6379 Pushing additional filters for disjunction of expressions past JOIN
• relates to: CALCITE-2241 Join equality condition should be considered while pushing down filter conditions with expressions disjunction for both tables
• relates to: DRILL-6350 Umbrella jira which tracks issues connected to Transitive Closure Inference