[CALCITE-4105] Replace Pair with Flat2List in RelDigestWriter to improve hash code distribution

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.24.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Haisheng Yuan
• Reporter: Haisheng Yuan
• Created: 03/Jul/20 20:12
• Updated: 25/Jul/20 14:59
• Resolved: 14/Jul/20 00:43

Description

Pair hashCode uses XOR, Flat2List uses 31 prime multiplication.

Issue Links

• links to: GitHub Pull Request #2058