[SOLR-12871] sort=childfield(currency_field) desc fails with exception about REWRITABLE field type

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 6.6
• Component/s: query parsers
• Assignee: Unassigned
• Reporter: Mikhail Khludnev
• Created: 15/Oct/18 19:14
• Updated: 08/Jun/19 15:01

Description

When searching by bjq and sorting by matching child currency field like 
sort=childfield(currency_field) desc it fails with

UnsupportedOperationException: Sort type REWRITEABLE is not supported
    at org.apache.lucene.search.join.ToParentBlockJoinSortField.<init>(ToParentBlockJoinSortField.java:65)

At least it's good to start documenting workaround. Btw why don't allow functions over children just by rewriting underneath sort field?  

Issue Links

• is related to: SOLR-10521 sort by string field of the nested child when searching with {!parent}