From time to time, in working with Solr there is a problem – how to update Solr index structure. There are various reasons for these changes – the new functional requirements, optimization, or anything else – it is not important. What is important is the question that arise – should we remove the index, or simply change the structure and do a full indexing? Contrary to appearances, the answer to this question depends on the changes we made in the structure of the index.