[IMPALA-13568] Calcite planner is falling back incorrectly for some select statements

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: Impala 4.5.0
• Component/s: Frontend
• Epic Color: ghx-label-3
• Assignee: Unassigned
• Reporter: Joe McDonnell
• Created: 6 days ago 21:25
• Updated: 6 days ago 21:25

Description

The Calcite planner tries to parse with the Calcite parser. If that fails, it checks whether this is a select statement by parsing with the regular parser and seeing if it is a SelectStmt. If it isn't, it falls back to the original planner. This is great for DDL/DML and other random statements not supported by Calcite, but this check is not quite right. This statement is a select, but it falls back to the original planner:

with t1 as (select int_col x, bigint_col y from alltypestiny),
t2 as (select 1 x , 10 y), t3 as (values(2 x , 20 y), (3, 30))
select * from t1 union all select * from t2 union all (select * from t3) order by x limit 20

The check should be comparing against QueryStmt, which is the base class for SelectStmt as well as SetOperationsStmt and UnionStmt.