Add logic to enable iceberg incremental tables.

.changes/unreleased/Features-20240923-203204.yaml

@@ -0,0 +1,6 @@
+kind: Features
+body: Add Iceberg format Incremental Models
+time: 2024-09-23T20:32:04.783741-07:00
+custom:
+    Author: versusfacit
+    Issue: "321"

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

@@ -58,12 +58,20 @@
 
 {% materialization incremental, adapter='snowflake', supported_languages=['sql', 'python'] -%}
 
-  {% set original_query_tag = set_query_tag() %}
 
   {#-- Set vars --#}
   {%- set full_refresh_mode = (should_full_refresh()) -%}
+  {%- set identifier = model['alias'] -%}
   {%- set language = model['language'] -%}
-  {% set target_relation = this %}
+
+  {%- set target_relation = api.Relation.create(
+	identifier=identifier,
+	schema=schema,
+	database=database,
+	type='table',
+	table_format=config.get('table_format', 'default')
+    ) -%}
+
   {% set existing_relation = load_relation(this) %}
 
   {#-- The temp relation will be a view (faster) or temp table, depending on upsert/merge strategy --#}
@@ -90,11 +98,22 @@
     {%- call statement('main', language=language) -%}
       {{ create_table_as(False, target_relation, compiled_code, language) }}
     {%- endcall -%}
+
   {% elif full_refresh_mode %}
+    {% if target_relation.needs_to_drop(existing_relation) %}
+      {{ drop_relation_if_exists(existing_relation) }}
+    {% endif %}
     {%- call statement('main', language=language) -%}
       {{ create_table_as(False, target_relation, compiled_code, language) }}
     {%- endcall -%}
 
+  {% elif target_relation.table_format != existing_relation.table_format %}
+    {% do exceptions.raise_compiler_error(
+        "Unable to convert a " ~ existing_relation.table_format ~ " format table to " ~
+        target_relation.table_format ~ " without specifying --full-refresh."
+      )
+    %}
+
   {% else %}
     {#-- Create the temp relation, either as a view or as a temp table --#}
     {% if tmp_relation_type == 'view' %}