[ARROW-11029] [Rust] [DataFusion] Document why join order optimization does not work with filter pushdown

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0
• Component/s: Rust - DataFusion
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/26948
• Assignee: Andy Grove
• Reporter: Andy Grove
• Created: 24/Dec/20 16:13
• Updated: 11/Jan/23 08:17
• Resolved: 02/Jan/21 08:31

Description

When I run TPC-H query 12, I see that the join order is not optimized to put the smaller table on the left. I added some debug logging and see that the optimization sees row count of None on the left side because there is a filter wrapping the table scan.

Issue Links

• links to: GitHub Pull Request #9007