[IGNITE-15530] IndexQuery has to use MergeSort reducer

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.12
• Labels: IEP-71
• Release Note: IndexQuery returns sorted over all nodes result
• Ignite Flags: Release Notes Required
• Assignee: Maksim Timonin
• Reporter: Maksim Timonin
• Reviewer: Anton Vinogradov
• Created: 16/Sep/21 16:10
• Updated: 06/May/24 10:35
• Resolved: 09/Nov/21 09:03

Description

Currently IndexQuery doesn't sort result over multiple nodes. But the idea of index is to return ordered result. So, IndexQuery should use MergeSort for a result cursor.

Issue Links

• causes: IGNITE-22168 Fix fieldsCount in TcpCommunication messages
• links to: GitHub Pull Request #9540