[HIVE-25884] Improve rule description for rules defined as subclasses

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0.0
• Fix Version/s: 4.0.0-alpha-1
• Component/s: CBO
• Labels: pull-request-available
• Assignee: Alessandro Solimando
• Reporter: Alessandro Solimando
• Created: 20/Jan/22 16:57
• Updated: 17/Nov/22 08:49
• Resolved: 17/Feb/22 13:40

Description

Consider the instances of HivePointLookupOptimizerRule (for joins, filters and projects).

They use the default constructor for RelOptRule, which builds the rule description from the class name, and in case of nested classes, it takes only the inner class name.

In this case, the names do not refer to HivePointLookupOptimizerRule and are too generic (e.g.,FilerCondition), it's hard to link them back to the rule they belong to without looking at the source code.

This is particularly problematic now that we have more detailed logging for CBO (see HIVE-25816), where rule descriptions are printed.

The aim of the PR is to improve the rule description by passing an explicit string whenever the rule (class) name alone is not enough.

Issue Links

• relates to: HIVE-25816 Log CBO plan after rule application for debugging purposes
• links to: GitHub Pull Request #2957