[IMPALA-11811] Avoid storing unregistered predicate objects in a Map

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Impala 4.2.0
• Fix Version/s: Impala 4.3.0
• Component/s: fe
• Epic Color: ghx-label-3
• Assignee: Andrew Sherman
• Reporter: Andrew Sherman
• Created: 23/Dec/22 02:40
• Updated: 26/Mar/23 06:22
• Resolved: 05/Jan/23 03:40

Description

Within the extractIcebergConjuncts() method we are tracking conjuncts which are identity conjuncts by storing them in a temporary Map.
The conjuncts are Expr objects which have a hashCode() method based on their id_ field, which is only present when they are registered.
If the id_ field is null, then the hashCode() will throw, and hence unregistered predicates cannot be stored in a Map.
This can happen if the conjuncts are bound predicates (produced by getBoundPredicates()) which are explicitly not registered.

Change extractIcebergConjuncts() to track the identity conjuncts in another way, perhaps using a boolean array which tracks the index of the identity conjuncts in conjuncts_ List.