[CALCITE-3722] Add Hook#PLAN_BEFORE_IMPLEMENTATION to capture the plan after optimization

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.21.0
• Fix Version/s: 1.22.0
• Component/s: core
• Assignee: Vladimir Sitnikov
• Reporter: Vladimir Sitnikov
• Created: 10/Jan/20 11:03
• Updated: 10/Jan/20 11:11
• Resolved: 10/Jan/20 11:11

Description

This helps to validate the execution plan, especially when sql-to-rel is implemented with a custom factory as in CalciteAssert#withRel.