Add adapter unique_field

CHANGELOG.md

@@ -4,6 +4,9 @@
 - Enhanced get_columns_in_relation method to handle a bug in open source deltalake which doesnt return schema details in `show table extended in databasename like '*'` query output. This impacts dbt snapshots if file format is open source deltalake ([#207](https://github.com/dbt-labs/dbt-spark/pull/207))
 - Parse properly columns when there are struct fields to avoid considering inner fields: Issue ([#202](https://github.com/dbt-labs/dbt-spark/issues/202))
 
+### Under the hood
+- Add `unique_field` to better understand adapter adoption in anonymous usage tracking ([#211](https://github.com/dbt-labs/dbt-spark/pull/211))
+
 ### Contributors
 - [@harryharanb](https://github.com/harryharanb) ([#207](https://github.com/dbt-labs/dbt-spark/pull/207))
 - [@SCouto](https://github.com/Scouto) ([#204](https://github.com/dbt-labs/dbt-spark/pull/204))

dbt/adapters/spark/connections.py

@@ -135,6 +135,10 @@ def __post_init__(self):
     def type(self):
         return 'spark'
 
+    @property
+    def unique_field(self):
+        return self.host
+
     def _connection_keys(self):
         return ('host', 'port', 'cluster',
                 'endpoint', 'schema', 'organization')