[LUCENE-9450] Taxonomy index should use DocValues not StoredFields

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 8.5.2
• Fix Version/s: 9.0
• Component/s: modules/facet
• Labels: performance
• Lucene Fields: New, Patch Available
• Review Patch?: Yes
• Assignee: Unassigned
• Reporter: Gautam Worah
• Created: 09/Aug/20 23:58
• Updated: 28/Aug/22 16:05
• Resolved: 16/Jan/21 11:47

Description

The taxonomy index that maps binning labels to ordinals was created before Lucene added BinaryDocValues.

I've attached a WIP patch (does not pass tests currently)

Issue suggested by mikemccand

Issue Links

• links to: GitHub Pull Request #220
• links to: GitHub Pull Request #1733