Update config documentation

Author: pepijnve

datafusion/common/src/config.rs

@@ -237,7 +237,7 @@ config_namespace! {
         /// The default schema name - this impacts what SQL queries use if not specified
         pub default_schema: String, default = "public".to_string()
 
-        /// The system schema name
+        /// The system schema name - when set a global system and [information_schema] catalog will be available
         pub system_catalog: Option<String>, default = None
 
         /// Should DataFusion provide access to `information_schema`

docs/source/user-guide/configs.md

@@ -68,6 +68,7 @@ The following configuration settings are available:
 | datafusion.catalog.create_default_catalog_and_schema                    | true                      | Whether the default catalog and schema should be created automatically.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
 | datafusion.catalog.default_catalog                                      | datafusion                | The default catalog name - this impacts what SQL queries use if not specified                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
 | datafusion.catalog.default_schema                                       | public                    | The default schema name - this impacts what SQL queries use if not specified                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| datafusion.catalog.system_catalog                                       | NULL                      | The system schema name - when set a global system and [information_schema] catalog will be available                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
 | datafusion.catalog.information_schema                                   | false                     | Should DataFusion provide access to `information_schema` virtual tables for displaying schema information                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
 | datafusion.catalog.location                                             | NULL                      | Location scanned to load tables for `default` schema                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
 | datafusion.catalog.format                                               | NULL                      | Type of `TableProvider` to use when loading `default` schema                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |