Hello. I'd probably describe this as a bug.
w.r.t. documentation adjustments e.g. https://github.com/apache/solr/blob/main/solr/solr-ref-guide/modules/indexing-guide/pages/schema-elements.adoc and https://github.com/apache/solr/blob/main/solr/solr-ref-guide/modules/query-guide/pages/result-grouping.adoc is the source behind the Solr Ref Guide and changes can be contributed via pull requests, just like with code. For small edits perhaps just working in your browser might suit and/or for more comprehensive information please see the https://github.com/apache/solr/blob/main/CONTRIBUTING.md#contributing-documentation details. Best wishes, Christine From: users@solr.apache.org At: 02/07/24 00:31:23 UTCTo: users@solr.apache.org Subject: Re: Group by query reports null pointer when unique key is not stored I also got this exception before and in order to avoid reindexing TB's of data, had to resort to grouping via streaming expressions, which has its ups and downs. If it's technically infeasible to substitute docValues for this purpose (when useDocValuesAsStored:true), it would be nice if it was documented in "grouping" feature or advised in general schema design pages to make unique ID's always stored:true. -ufuk yilmaz ________________________________ From: rajani m <rajinima...@gmail.com> Sent: Wednesday, February 7, 2024 3:18 AM To: solr-user <solr-u...@lucene.apache.org> Subject: Group by query reports null pointer when unique key is not stored Hi Solr Users, Group by query is failing with the following error message. It looks like TopGroupsResultTransformer.java <https://github.com/apache/solr/blob/main/solr/core/src/java/org/apache/solr/sea rch/grouping/distributed/shardresultserializer/TopGroupsResultTransformer.java#L 237C24-L237C40> retrieveDocument method is fetching doc based on id is calling a stored field visitor method. I tried setting the "id" field to use doc values as they are enabled "useDocValuesAsStored:true" but this didn't help. Any alternative? Would you call this a bug or improvement? Error message - java.lang.NullPointerException: Cannot invoke "org.apache.lucene.index.IndexableField.stringValue()" because "f" is null => java.lang.NullPointerException: Cannot invoke "org.apache.lucene.index.IndexableField.stringValue()" because "f" is null at org.apache.solr.schema.FieldType.toExternal(FieldType.java:378) java.lang.NullPointerException: Cannot invoke "org.apache.lucene.index.IndexableField.stringValue()" because "f" is null at org.apache.solr.schema.FieldType.toExternal(FieldType.java:378) ~[?:?] at org.apache.solr.search.grouping.distributed.shardresultserializer.TopGroupsResul tTransformer.serializeTopGroups(TopGroupsResultTransformer.java:238) ~[?:?]
