[CALCITE-360] Introduce a Rule to infer predicates from equi join conditions.

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.9.0-incubating
• Assignee: Julian Hyde
• Reporter: Harish Butani
• Created: 05/Aug/14 01:19
• Updated: 19/Dec/14 18:27
• Resolved: 06/Aug/14 19:50

Description

This is along the lines of the TransitivePredicate inference Rule in Hive.
For e.g. for

select 1 from sales.emp d inner join sales.emp e 
on d.deptno = e.deptno where e.deptno > 7

we can infer

ProjectRel(EXPR$0=[1])
  JoinRel(condition=[=($7, $16)], joinType=[inner])
    FilterRel(condition=[>($7, 7)])
      TableAccessRel(table=[[CATALOG, SALES, EMP]])
    FilterRel(condition=[>($7, 7)])
      TableAccessRel(table=[[CATALOG, SALES, EMP]])

More egs in the patch. We can do better than Hive: by pulling up Predicates that are effective above every RelNode and inferring new Predicates for the other side of a Join.

Issue Links

• is duplicated by: CALCITE-41 Add rule to propagate constraints onto aliased columns