[SOLR-15440] contrib/ltr FieldValueFeature: DocValues use for stored fields

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: main (10.0), 9.4
• Component/s: contrib - LTR
• Assignee: Christine Poerschke
• Reporter: Christine Poerschke
• Created: 27/May/21 10:51
• Updated: 15/Oct/23 19:57
• Resolved: 15/Sep/23 11:43

Description

SOLR-12697 in Solr 8.9 is intending to add FieldValueFeature support "stored=false docValues=true" a.k.a. pure DocValues fields.

The SOLR-12697 changes are implemented in a backwards compatible manner i.e. existing behaviour for "stored=trued docValues=true" a.k.a. stored DocValues fields does not change.

This ticket here is to explore how backwards compatibility could potentially be broken (in a safe manner) in future e.g.

• Solr 9.4 breaks backwards compatibility for FieldValueFeature but provides a deprecated LegacyFieldValueFeature with the existing behaviour for users who need that.
• Solr 9.X or 10.0 removes the deprecated LegacyFieldValueFeature class and users still needing the legacy behaviour need to create and maintain an equivalent local custom class.

Issue Links

• is related to: SOLR-12697 pure DocValues support for FieldValueFeature
• links to: GitHub Pull Request #1883
• links to: https://github.com/apache/solr/pull/1883