It looks to me like the showItems argument for the fieldValueCache is not used. I can’t find any documentation of it, although it was mentioned in the changelog for v8.1.0.
I looked through the source and I can’t see where the value is used. It gets a default value, but never seems to be used, based on my understanding of the source code. $ grep -w showItems -R . ./solr/core/src/java/org/apache/solr/core/SolrConfig.java: args.put("showItems", "-1"); ./solr/core/src/java/org/apache/solr/search/SolrCache.java: String SHOW_ITEMS_PARAM = "showItems"; ./solr/core/src/test-files/solr/configsets/exitable-directory/conf/solrconfig.xml: showItems="0" /> ./solr/server/solr/configsets/_default/conf/solrconfig.xml: showItems="32" /> ./solr/server/solr/configsets/sample_techproducts_configs/conf/solrconfig.xml: showItems="32" /> ./solr/CHANGES.txt:* SOLR-13432: Add .toString methods to BitDocSet and SortedIntDocSet so that enabling "showItems" on the filter caches $ grep -w SHOW_ITEMS_PARAM -R . ./solr/core/src/java/org/apache/solr/search/SolrCache.java: String SHOW_ITEMS_PARAM = "showItems”; Is it a leftover from long ago? If so, I’ll put in a patch to remove its last vestiges from the source and from the sample config files. Thanks, Andy