One of the configuration files that describe each implementation Solr is schema.xml file. It describes one of the most important things of the implementation – the structure of the data index. The information contained in this file allow you to control how Solr behaves when indexing the data, or when making queries. Schema.xml is not only the very structure of the index, is also detailed information about data types that have a large influence on the behavior Solr, and usually are treated with neglect. This entry will try to bring some insight about schema.xml.