[ARROW-16600] [Java] Enable configurable scale coercion of BigDecimal

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 8.0.0
• Fix Version/s: 9.0.0
• Component/s: Java
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/31954
• Assignee: Todd Farmer
• Reporter: Todd Farmer
• Created: 17/May/22 19:39
• Updated: 11/Jan/23 11:45
• Resolved: 27/Jun/22 15:27

Description

Per ARROW-16427, JDBC drivers sometimes return ResultSets where the scale of BigDecimals in a single column differs by row.  The existing mapping requires exact match of scale to the target Arrow vector that was created based on ResultSetMetaData (or configuration), and when any row does not match exactly, an Exception is thrown.

To support JDBC drivers where scale may be inconsistent by row, Arrow should allow a less-strict mode that coerces BigDecimals to target vectors with greater scale.  The default strict behavior should be retained, but it may be useful to allow coercion to proper target scale. 

Issue Links

• is related to: ARROW-16427 [Java] jdbcToArrowVectors / sqlToArrowVectorIterator fails to handle variable decimal precision / scale
• links to: GitHub Pull Request #13433