Avoid describe extended on hive_metastore (#446)

CHANGELOG.md

@@ -3,6 +3,7 @@
 ### Fixes
 
 - Fixed an issue with AWS OAuth M2M flow ([#445](https://github.com/databricks/dbt-databricks/pull/445))
+- Fixed an issue where every table in hive_metastore would get described ([#446](https://github.com/databricks/dbt-databricks/pull/446))
 
 ## dbt-databricks 1.6.3 (September 8, 2023)
 

dbt/adapters/databricks/impl.py

@@ -264,6 +264,8 @@ def typeFromNames(
                         if view_names[name]
                         else DatabricksRelationType.View
                     )
+                elif database is None or database == "hive_metastore":
+                    return DatabricksRelationType.Table
                 else:
                     # not a view so it might be a streaming table
                     # get extended information to determine

tests/integration/avoid_describe_extended/models/new_model.sql

@@ -0,0 +1,7 @@
+{{ config(
+    materialized = 'table'
+) }}
+
+select cast(1 as bigint) as id, 'hello' as msg
+union all
+select cast(2 as bigint) as id, 'goodbye' as msg

tests/integration/avoid_describe_extended/seeds/preexisting_data.csv

@@ -0,0 +1,5 @@
+id,msg
+1,hello
+2,goodbye
+2,yo
+3,anyway

tests/integration/avoid_describe_extended/test_avoid_describe_extended.py

@@ -0,0 +1,33 @@
+from tests.integration.base import DBTIntegrationTest, use_profile
+
+
+class TestAvoidDescribeExtended(DBTIntegrationTest):
+    """Tests in this class exist to ensure we don't call describe extended unnecessarily.
+    This became a problem due to needing to discern tables from streaming tables, which is not
+    relevant on hive, but users on hive were having all of their tables describe extended-ed.
+    We only need to call describe extended if we are using a UC catalog and we can't determine the
+    type of the materialization."""
+
+    @property
+    def schema(self):
+        return "schema"
+
+    @property
+    def models(self):
+        return "models"
+
+    def _test_avoid_describe_extended(self):
+        # Add some existing data to ensure we don't try to 'describe extended' it.
+        self.run_dbt(["seed"])
+        _, log_output = self.run_dbt_and_capture(["run"])
+        self.assertNotIn("describe extended", log_output)
+
+    @use_profile("databricks_cluster")
+    def test_avoid_describe_extended_databricks_cluster(self):
+        """When UC is not enabled, we can assumed that all tables are regular tables"""
+        self._test_avoid_describe_extended()
+
+    @use_profile("databricks_uc_sql_endpoint")
+    def test_avoid_describe_extended_databricks_uc_sql_endpoint(self):
+        """When UC is enabled, regular tables are marked as such"""
+        self._test_avoid_describe_extended()