[SPARK-49131] TransformWithState doesn't set implicit grouping key when lazy iterators are used

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0.0
• Fix Version/s: 4.0.0
• Component/s: Structured Streaming
• Labels: pull-request-available
• Assignee: Neil Ramaswamy
• Reporter: Neil Ramaswamy
• Created: 06/Aug/24 21:58
• Updated: 20/Aug/24 01:17
• Resolved: 20/Aug/24 01:17

Description

When a lazy iterator is used, the implicit key for state updates in TWS is not set properly. This is because the implicit key is set as a thread local only when `handleInputRows` is called, not when methods on the returned iterator are invoked. Both eager and lazy iterators should be supported.

Issue Links

• links to: GitHub Pull Request #47641