[HIVE-12017] Do not disable CBO by default when number of joins in a query is equal or less than 1

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0
• Fix Version/s: 2.0.0
• Component/s: CBO
• Target Version/s: 2.0.0
• Assignee: Jesús Camacho Rodríguez Assign to me
• Reporter: Jesús Camacho Rodríguez
• Created: 02/Oct/15 15:41
• Updated: 27/Feb/24 22:24
• Resolved: 20/Nov/15 22:34

Description

Instead, we could disable some parts of CBO that are not relevant if the query contains 1 or 0 joins. Implementation should be able to define easily other query patterns for which we might disable some parts of CBO (in case we want to do it in the future).

Issue Links

• duplicates: HIVE-12040 CBO: Use CBO, even for the 1 JOIN + GROUP BY case
• incorporates: HIVE-12509 Regenerate q files after HIVE-12017 went in
• is blocked by: HIVE-12391 SkewJoinOptimizer might not kick in if columns are renamed after TableScanOperator
• relates to: HIVE-12465 Hive might produce wrong results when (outer) joins are merged
• relates to: HIVE-12477 Left Semijoins are incompatible with a cross-product
• links to: RB link