[LUCENE-3423] add Terms.docCount

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0-ALPHA
• Lucene Fields: New
• Assignee: Robert Muir
• Reporter: Robert Muir
• Created: 08/Sep/11 21:59
• Updated: 28/Aug/22 12:56
• Resolved: 11/Sep/11 13:25

Description

spinoff from LUCENE-3290, where yonik mentioned:

Is there currently a way to get the number of documents that have a value in the field?
Then one could compute the average length of a (sparse) field via sumTotalTermFreq(field)/docsWithField(field)
docsWithField(field) would be useful in other contexts that want to know how sparse a field is (automatically selecting faceting algorithms, etc).

I think this is a useful stat to add, in case you have sparse fields for heuristics or scoring.