[CALCITE-6464] Type inference for DECIMAL division seems incorrect

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.37.0
• Fix Version/s: 1.38.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Mihai Budiu
• Reporter: Mihai Budiu
• Created: 11/Jul/24 07:00
• Updated: 17/Oct/24 22:41
• Resolved: 17/Oct/24 22:41

Description

This bug surfaces if one uses a custom type system, e.g., where DECIMAL is limited to (28, 10).
The problem is in RelDataTypeSystem.deriveDecimalDivideType.
The JavaDoc of this function gives the algorithm for deriving the division result type.
According to these rules, if you divide two numbers of type DECIMAL(28, 10), you should get a result with type DECIMAL(28, 10).
But the actual implementation infers a type of DECIMAL(28, 0), which seems incorrect.

Issue Links

• is related to: CALCITE-6533 Division between integer and decimal produces incorrect result
• relates to: CALCITE-6602 Deadlock while loading class SqlTypeFixture
• links to: GitHub Pull Request #3855
• links to: GitHub Pull Request #3906