[LUCENE-4607] Add estimateDocCount to DocIdSetIterator

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0
• Fix Version/s: 4.3, 6.0
• Component/s: core/search
• Lucene Fields: New, Patch Available
• Assignee: Unassigned
• Reporter: Simon Willnauer
• Created: 10/Dec/12 14:52
• Updated: 28/Aug/22 13:33
• Resolved: 14/Mar/13 21:20

Description

this is essentially a spinnoff from LUCENE-4236
We currently have no way to make any decsision on how costly a DISI is neither when we apply filters nor when we build conjunctions in BQ. Yet we have most of the information already and can easily expose them via a cost API such that BS and FilteredQuery can apply optimizations on per segment basis.

Issue Links

• is depended upon by: LUCENE-5424 FilteredQuery useRandomAccess() should use cost()
• relates to: LUCENE-4236 clean up booleanquery conjunction optimizations a bit