[SPARK-48100] [SQL][XML] Fix issues in skipping nested structure fields not selected in schema

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0.0
• Fix Version/s: 4.0.0
• Component/s: SQL
• Labels: pull-request-available
• Assignee: Shujing Yang
• Reporter: Shujing Yang
• Created: 02/May/24 22:14
• Updated: 15/May/24 04:59
• Resolved: 15/May/24 04:59

Description

Previously, the XML parser can't skip nested structure data fields effectively when they were not selected in the schema. For instance, in the below example, `df.select("struct2").collect()` returns `Seq(null)` as `struct1` wasn't effectively skipped. This PR fixes this issue.

<ROW>
  <struct1>
    <innerStruct><field1>1</field1></innerStruct>
  </struct1>
  <struct2>
    <field2>2</field2>
  </struct2>
</ROW>

 

Issue Links

• links to: GitHub Pull Request #46348