Add a fast-path option for loading dbt's seed files via a DuckDB COPY operation

dbt/adapters/duckdb/impl.py

@@ -56,6 +56,10 @@ def convert_datetimes_to_strs(self, table: agate.Table) -> agate.Table:
                 )
         return table
 
+    @available
+    def get_seed_file_path(self, model) -> str:
+        return os.path.join(model["root_path"], model["original_file_path"])
+
     @available
     def location_exists(self, location: str) -> bool:
         try:

dbt/include/duckdb/macros/seed.sql

@@ -8,6 +8,15 @@
 {% endmacro %}
 
 {% macro duckdb__load_csv_rows(model, agate_table) %}
+    {% if config.get('fast') %}
+        {% set seed_file_path = adapter.get_seed_file_path(model) %}
+        {% set sql %}
+          COPY {{ this.render() }} FROM '{{ seed_file_path }}' (FORMAT CSV, HEADER TRUE)
+        {% endset %}
+        {% do adapter.add_query(sql, abridge_sql_log=True) %}
+        {{ return(sql) }}
+    {% endif %}
+
     {% set batch_size = get_batch_size() %}
     {% set agate_table = adapter.convert_datetimes_to_strs(agate_table) %}
     {% set cols_sql = get_seed_column_quoted_csv(model, agate_table.column_names) %}

tests/functional/adapter/simple_seed/test_fast_seed.py

@@ -0,0 +1,17 @@
+import pytest
+
+from dbt.tests.adapter.simple_seed.test_seed import SeedTestBase
+from dbt.tests.util import (
+    run_dbt,
+)
+
+class TestSeedConfigFast(SeedTestBase):
+    @pytest.fixture(scope="class")
+    def project_config_update(self):
+        return {
+            "seeds": {"quote_columns": False, "fast": True}
+        }
+
+    def test_simple_seed_fast(self, project):
+        self._build_relations_for_test(project)
+        self._check_relation_end_state(run_result=run_dbt(["seed"]), project=project, exists=True)