[SOLR-14765] optimize DocList creation by skipping sort for sort-irrelevant cases

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 9.0
• Fix Version/s: 9.1
• Labels: pull-request-available
• Assignee: Michael Gibney
• Reporter: Michael Gibney
• Created: 20/Aug/20 03:05
• Updated: 09/Oct/24 16:57
• Resolved: 04/Apr/22 20:16

Description

When rows=0, and for MatchAllDocsQuery and ConstantScoreQuery (and possibly others?), it is possible for SolrIndexSearcher.getDocListC(QueryResult, QueryCommand) to create a DocList directly from filterCache DocSets – similar to useFilterForSortedQuery, but without actually sorting.

This results in significant benefits for high-recall domains, including the common (and commonly-cached) use-case of q=*:* and fq, facets, etc.

Issue Links

• causes: SOLR-16587 Solr 9.1.0 last page retrieval error
• causes: SOLR-16585 All docs query with any nonzero positive start value throws NPE with "this.docs is null"
• links to: GitHub Pull Request #592
• links to: GitHub Pull Request #1766
• links to: GitHub Pull Request #2682