Apply "Initial refactoring of incremental materialization"

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## dbt-databricks 1.3.0 (Release TBD)
 
+### Under the hood
+- Apply "Initial refactoring of incremental materialization" ([#148](https://github.com/databricks/dbt-databricks/pull/148))
+    - Now dbt-databricks uses `adapter.get_incremental_strategy_macro` instead of `dbt_spark_get_incremental_sql` macro to dispatch the incremental strategy macro. The overwritten `dbt_spark_get_incremental_sql` macro will not work anymore.
+
 ## dbt-databricks 1.2.1 (August 24, 2022)
 
 ### Features

dbt/adapters/databricks/impl.py

@@ -211,6 +211,9 @@ def _get_columns_for_catalog(self, relation: DatabricksRelation) -> Iterable[Dic
             as_dict["column_type"] = as_dict.pop("dtype")
             yield as_dict
 
+    def valid_incremental_strategies(self) -> List[str]:
+        return ["append", "merge", "insert_overwrite"]
+
     @contextmanager
     def _catalog(self, catalog: Optional[str]) -> Iterator[None]:
         """

dbt/include/databricks/macros/materializations/incremental/incremental.sql

@@ -6,7 +6,7 @@
   {%- set grant_config = config.get('grants') -%}
 
   {%- set file_format = dbt_spark_validate_get_file_format(raw_file_format) -%}
-  {%- set strategy = dbt_spark_validate_get_incremental_strategy(raw_strategy, file_format) -%}
+  {%- set incremental_strategy = dbt_spark_validate_get_incremental_strategy(raw_strategy, file_format) -%}
 
   {%- set unique_key = config.get('unique_key', none) -%}
   {%- set partition_by = config.get('partition_by', none) -%}
@@ -17,9 +17,8 @@
 
   {% set target_relation = this %}
   {% set existing_relation = load_relation(this) %}
-  {% set tmp_relation = make_temp_relation(this) %}
 
-  {% if strategy == 'insert_overwrite' and partition_by %}
+  {% if incremental_strategy == 'insert_overwrite' and partition_by %}
     {% call statement() %}
       set spark.sql.sources.partitionOverwriteMode = DYNAMIC
     {% endcall %}
@@ -37,9 +36,12 @@
     {% endif %}
     {% set build_sql = create_table_as(False, target_relation, sql) %}
   {% else %}
-    {% do run_query(create_table_as(True, tmp_relation, sql)) %}
-    {% do process_schema_changes(on_schema_change, tmp_relation, existing_relation) %}
-    {% set build_sql = dbt_spark_get_incremental_sql(strategy, tmp_relation, target_relation, unique_key) %}
+    {% set temp_relation = make_temp_relation(this) %}
+    {% do run_query(create_table_as(True, temp_relation, sql)) %}
+    {% do process_schema_changes(on_schema_change, temp_relation, existing_relation) %}
+    {% set strategy_sql_macro_func = adapter.get_incremental_strategy_macro(context, incremental_strategy) %}
+    {% set strategy_arg_dict = ({'target_relation': target_relation, 'temp_relation': temp_relation, 'unique_key': unique_key }) %}
+    {% set build_sql = strategy_sql_macro_func(strategy_arg_dict) %}
   {% endif %}
 
   {%- call statement('main') -%}

dbt/include/databricks/macros/materializations/incremental/strategies.sql

@@ -0,0 +1,15 @@
+{% macro databricks__get_incremental_default_sql(arg_dict) %}
+  {{ return(get_incremental_merge_sql(arg_dict)) }}
+{% endmacro %}
+
+{% macro databricks__get_incremental_append_sql(arg_dict) %}
+  {% do return(get_insert_into_sql(arg_dict["temp_relation"], arg_dict["target_relation"])) %}
+{% endmacro %}
+
+{% macro databricks__get_incremental_merge_sql(arg_dict) %}
+  {% do return(get_merge_sql(arg_dict["target_relation"], arg_dict["temp_relation"], arg_dict["unique_key"], dest_columns=none, predicates=none)) %}
+{% endmacro %}
+
+{% macro databricks__get_incremental_insert_overwrite_sql(arg_dict) %}
+  {% do return(get_insert_overwrite_sql(arg_dict["temp_relation"], arg_dict["target_relation"])) %}
+{% endmacro %}