document DWS hierarchy table DDL

sql/chpa/02_dws/01_dws_ext_td_ims_atc_hierarchy.sql

@@ -10,6 +10,14 @@
 -- Notes      : Parent-code matching is preserved from the legacy script.
 -- =============================================================================
 
+-- COMMAND ----------
+
+-- One-time DDL: copy the verified legacy schema without copying data.
+-- CREATE TABLE IF NOT EXISTS dws.dws_ext_td_ims_atc_hierarchy
+-- LIKE dwd.dwd_ims_atc_hierarchy;
+
+-- COMMAND ----------
+
 INSERT OVERWRITE TABLE dws.dws_ext_td_ims_atc_hierarchy (
     ATC1_ID,
     ATC1_CODE,

sql/chpa/02_dws/02_dws_ext_td_ims_nfc_hierarchy.sql

@@ -10,6 +10,14 @@
 -- Notes      : Parent-code matching is preserved from the legacy script.
 -- =============================================================================
 
+-- COMMAND ----------
+
+-- One-time DDL: copy the verified legacy schema without copying data.
+-- CREATE TABLE IF NOT EXISTS dws.dws_ext_td_ims_nfc_hierarchy
+-- LIKE dwd.dwd_ims_nfc_hierarchy;
+
+-- COMMAND ----------
+
 INSERT OVERWRITE TABLE dws.dws_ext_td_ims_nfc_hierarchy (
     NFC1_ID,
     NFC1_CODE,