diff --git a/dbt/include/greenplum/macros/materializations/snapshot_merge.sql b/dbt/include/greenplum/macros/materializations/snapshot_merge.sql
index f7f64b4..7e5b157 100644
--- a/dbt/include/greenplum/macros/materializations/snapshot_merge.sql
+++ b/dbt/include/greenplum/macros/materializations/snapshot_merge.sql
@@ -1,4 +1,132 @@
-
 {% macro greenplum__snapshot_merge_sql(target, source, insert_cols) -%}
-  {{ return(greenplum__snapshot_merge_sql(target, source, insert_cols)) }}
+    {%- set insert_cols_csv = insert_cols | join(', ') -%}
+
+    update {{ target }}
+    set dbt_valid_to = DBT_INTERNAL_SOURCE.dbt_valid_to
+    from {{ source }} as DBT_INTERNAL_SOURCE
+    where DBT_INTERNAL_SOURCE.dbt_scd_id::text = {{ target }}.dbt_scd_id::text
+      and DBT_INTERNAL_SOURCE.dbt_change_type::text in ('update'::text, 'delete'::text)
+      and {{ target }}.dbt_valid_to is null;
+
+    insert into {{ target }} ({{ insert_cols_csv }})
+    select {% for column in insert_cols -%}
+        DBT_INTERNAL_SOURCE.{{ column }} {%- if not loop.last %}, {%- endif %}
+    {%- endfor %}
+    from {{ source }} as DBT_INTERNAL_SOURCE
+    where DBT_INTERNAL_SOURCE.dbt_change_type::text = 'insert'::text;
 {% endmacro %}
+
+{% macro greenplum__snapshot_staging_table(strategy, source_sql, target_relation) -%}
+
+    with snapshot_query as (
+
+        {{ source_sql }}
+
+    ),
+
+    snapshotted_data as (
+
+        select *,
+            {{ strategy.unique_key }} as dbt_unique_key
+
+        from {{ target_relation }}
+        where dbt_valid_to is null
+
+    ),
+
+    insertions_source_data as (
+
+        select
+            *,
+            {{ strategy.unique_key }} as dbt_unique_key,
+            {{ strategy.updated_at }} as dbt_updated_at,
+            {{ strategy.updated_at }} as dbt_valid_from,
+            nullif({{ strategy.updated_at }}, {{ strategy.updated_at }}) as dbt_valid_to,
+            {{ strategy.scd_id }} as dbt_scd_id
+
+        from snapshot_query
+    ),
+
+    updates_source_data as (
+
+        select
+            *,
+            {{ strategy.unique_key }} as dbt_unique_key,
+            {{ strategy.updated_at }} as dbt_updated_at,
+            {{ strategy.updated_at }} as dbt_valid_from,
+            {{ strategy.updated_at }} as dbt_valid_to
+
+        from snapshot_query
+    ),
+
+    {%- if strategy.invalidate_hard_deletes %}
+
+    deletes_source_data as (
+
+        select
+            *,
+            {{ strategy.unique_key }} as dbt_unique_key
+        from snapshot_query
+    ),
+    {% endif %}
+
+    insertions as (
+
+        select
+            'insert'::text as dbt_change_type,
+            source_data.*
+
+        from insertions_source_data as source_data
+        left outer join snapshotted_data on snapshotted_data.dbt_unique_key = source_data.dbt_unique_key
+        where snapshotted_data.dbt_unique_key is null
+           or (
+                snapshotted_data.dbt_unique_key is not null
+            and (
+                {{ strategy.row_changed }}
+            )
+        )
+
+    ),
+
+    updates as (
+
+        select
+            'update'::text as dbt_change_type,
+            source_data.*,
+            snapshotted_data.dbt_scd_id
+
+        from updates_source_data as source_data
+        join snapshotted_data on snapshotted_data.dbt_unique_key = source_data.dbt_unique_key
+        where (
+            {{ strategy.row_changed }}
+        )
+    )
+
+    {%- if strategy.invalidate_hard_deletes -%}
+    ,
+
+    deletes as (
+
+        select
+            'delete'::text as dbt_change_type,
+            source_data.*,
+            {{ snapshot_get_time() }} as dbt_valid_from,
+            {{ snapshot_get_time() }} as dbt_updated_at,
+            {{ snapshot_get_time() }} as dbt_valid_to,
+            snapshotted_data.dbt_scd_id
+
+        from snapshotted_data
+        left join deletes_source_data as source_data on snapshotted_data.dbt_unique_key = source_data.dbt_unique_key
+        where source_data.dbt_unique_key is null
+    )
+    {%- endif %}
+
+    select * from insertions
+    union all
+    select * from updates
+    {%- if strategy.invalidate_hard_deletes %}
+    union all
+    select * from deletes
+    {%- endif %}
+
+{%- endmacro %}
\ No newline at end of file