[LUCENE-7834] BlockTree's terms index should be loaded into memory lazily

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Component/s: core/codecs
• Lucene Fields: New, Patch Available
• Assignee: David Smiley
• Reporter: David Smiley
• Created: 17/May/17 18:11
• Updated: 28/Aug/22 15:15
• Resolved: 02/Jun/17 14:38

Description

I propose that BlockTree delay loading the FST prefix terms index into memory until terms(String) is first called. This seems like how it should work since if someone wants to eager load then they can use IndexReaderWarmer. By making the FST lazy load, we can be more NRT friendly (if some fields are rarely used), and also save memory (if some fields are rarely used).

Issue Links

• relates to: LUCENE-7826 Support to unload FST's .tip into memory,make load or unload configuable!.