Merge pull request elementary-data#964 from elementary-data/ele-937-t…

…able-materialization-in-sync-doesnt-do-db-migrations

Schema changes are applied to table materialized models.

elementary/monitor/dbt_project/dbt_project.yml

@@ -38,3 +38,5 @@ quoting:
 # as tables. These settings can be overridden in the individual model files
 # using the `{{ config(...) }}` macro.
 models:
+  # Required in order to apply table schema changes in the table materialization.
+  +on_schema_change: "append_new_columns"

elementary/monitor/dbt_project/macros/materializations/table.sql

@@ -4,23 +4,17 @@
     {{ return(dbt.materialization_table_default()) }}
   {% endif %}
 
-  {% set existing_relation = load_cached_relation(this) %}
-  {% if not existing_relation %}
-    {% set init_schema_sql %}
-      with result as (
-        {{ sql }}
-      )
-      select * from result where 1 = 0
-    {% endset %}
-    {% do context.update({"sql": init_schema_sql}) %}
-  {# This is meant to deal with a race between initializing the table and loading data into it. #}
-  {% else %}
-    {% set same_sql %}
-      select * from {{ this }}
-    {% endset %}
-    {% do context.update({"sql": same_sql}) %}
-  {% endif %}
-
-  {% do context.update({"pre_hooks": [], "post_hooks": []}) %}
-  {{ return(dbt.materialization_table_default()) }}
+  {% set init_schema_sql %}
+    with result as (
+      {{ sql }}
+    )
+    select * from result where 1 = 0
+  {% endset %}
+  {% do context.update({
+    "sql": init_schema_sql,
+    "pre_hooks": [],
+    "post_hooks": [],
+    }) %}
+  {# We call the incremental materialization in order to hand-off the implementation of schema changes to dbt. #}
+  {{ return(dbt.materialization_incremental_default()) }}
 {% endmaterialization %}