[LUCENE-10245] Allow users to provide DocValues to (some) Facets Implementations

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 9.1, 10.0 (main)
• Component/s: modules/facet
• Lucene Fields: New
• Assignee: Greg Miller
• Reporter: Greg Miller
• Created: 19/Nov/21 14:48
• Updated: 28/Aug/22 16:30
• Resolved: 10/Jan/22 22:04

Description

We have some Facets implementations that do aggregations over numeric values associated with each doc (e.g., DoubleRangeFacetCounts, LongValueFacetCounts, etc.). These implementations allow the user to either specify, 1) a field to source the doc values from, or 2) a custom source of values in the form of DoubleValueSource, LongValueSource, etc.

Unfortunately, these xxValueSource implementations don't support multiple values per doc, while indexed doc values do. So if the user has indexed doc values they want to facet over, it works just fine if docs are multi-valued. But if they want to provide a custom source of data, they're restricted to single-value only.

We should consider allowing users to provide their own doc values instances in favor of the xxValueSource instances. (I'd propose we deprecate the xxValueSource approach)

Issue Links

• links to: GitHub Pull Request #543