Automatically fall back to truncate if no key_properties

setup.py

@@ -11,7 +11,7 @@
 
 setup(
     name="target-bigquery",
-    version="0.11.13",
+    version="0.11.14",
     description="Singer.io target for writing data to Google BigQuery",
     author="Adswerve",
     url="https://github.com/adswerve/target-bigquery",

target_bigquery/processhandler.py

@@ -307,9 +307,17 @@ def _do_temp_table_based_load(self, rows):
                 self.create_missing_columns(stream)
                 incremental_success = False
                 instance_truncate = self.truncate or self.table_configs.get(stream, {}).get("truncate", False) or self.table_configs.get(stream, {}).get("replication_method") == "truncate"
+                instance_increment = self.incremental if not instance_truncate else False
+
+                key_properties = [k.replace(".", "_") for k in self.key_properties[stream]]
+
+                if instance_increment and not key_properties:
+                    # Fall back to truncate because there's no PK to upsert on
+                    self.logger.info(f"Falling back to truncate because {stream} has no key properties")
+                    instance_truncate = True
+
                 if instance_truncate:
                     self.logger.info(f"Truncating dataset: {stream}")
-                instance_increment = self.incremental if not instance_truncate else False
                 # For larger jobs we don't want to keep truncating the same table when copy temporary table to production
                 # using this change we will switch truncate logic off and make subsequent copies to incremental
                 if stream in self.truncate_counts and self.truncate_counts.get(stream, 0) > 0: