make model incremental

models/staging/xedotcom/stg_xedotcom__exchange_rates.sql

@@ -1,3 +1,5 @@
+{{ config(materialized="incremental", unique_key="id_exchange_rate") }}
+
 with
     raw_exchange_rates as (select * from {{ source("xedotcom", "exchange_rates") }}),
     stg_xedotcom__exchange_rates as (
@@ -17,3 +19,8 @@ with
     )
 select *
 from stg_xedotcom__exchange_rates
+{% if is_incremental() %}
+    where
+        dwh_extracted_at_utc
+        >= ((select max(dwh_extracted_at_utc) from {{ this }}) - interval '7 days')
+{% endif %}