Hello! It is used internally by Solr, for example by features like partial update functionality and update log.
-- Regards, Rafał Kuć Sematext :: http://sematext.com/ :: Solr - Lucene - Nutch - ElasticSearch > I ma moving to solr4.0 from beta version. There is a exception was thrown, > Caused by: org.apache.solr.common.SolrException: _version_field must exist > in schema, using indexed="true" stored="true" and multiValued="false" > (_version_ does not exist) > at > org.apache.solr.update.VersionInfo.getAndCheckVersionField(VersionInfo.java:57) > at org.apache.solr.core.SolrCore.<init>(SolrCore.java:606) > ... 26 more > 2 > It's seem that there need a field like > <field name="_version_" type="long" indexed="true" stored="true"/> > in schema.xml. I am wonder what does this used for?
