[SOLR-5478] Optimization: Fetch all "fl" values from docValues instead of stored values if possible/equivalent

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 4.5
• Fix Version/s: 4.9, 6.0
• Component/s: Response Writers
• Assignee: Unassigned
• Reporter: Manuel Lenormand
• Created: 20/Nov/13 19:04
• Updated: 21/Nov/19 00:42
• Resolved: 19/Sep/17 03:41

Description

When the "fl" field list mentions a list of fields that all have docValues, and they are equivalent to the stored version (not true for multiValued field due to ordering), then we can fetch the values more efficiently from docValues than from stored values. If this can't be done, might as well fetch them all from stored values when they have both (this is what happens today).

Former title: Speed-up distributed search with high rows param or deep paging by transforming docId's to uniqueKey via memory docValues

Originally the scope of this was just for the uniqueKey but now it's broader.

Issue Links

• is duplicated by: SOLR-6888 Decompressing documents on first-pass distributed queries to get docId is inefficient, use indexed values instead?
• is related to: SOLR-6810 Faster searching limited but high rows across many shards all with many hits
• relates to: SOLR-5968 BinaryResponseWriter fetches unnecessary stored fields when only pseudo-fields are requested
• relates to: SOLR-8344 Decide default when requested fields are both column and row stored.
• relates to: SOLR-8220 Read field from docValues for non stored fields