All the information about fields and field types is mentioned in the schema file of Solr. Now, the schema file can be in one of the following places depending on how you have configured Solr:
- If you use ClassicIndexSchemaFactory, you would be manually editing the schema file which is named schema.xml by default
- If you decide to make schema changes at runtime using either the Schema API or schemaless mode, then the schema file is managed in the managed-schema file.
In the case of SolrCloud, you will make changes to the schema using Solr's admin UI or Schema API if it is enabled. In such a case, you will not be able to find either schema.xml or managed-schema.xml.