refs #730: add ADB PostgreSQL federation recording scripts

sql/adb/76_hmm_rds_pg_03_dblink.sql

@@ -0,0 +1,24 @@
+-- ============================================================
+-- Step 3: create an Oracle-managed PostgreSQL Database Link.
+-- Based on FY26 internal training, section 3.2.3.
+-- Run as ADMIN.
+-- Redmine: #730
+-- ============================================================
+
+BEGIN
+  DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK(
+    db_link_name       => 'HMM_RDS_PG_LINK',
+    hostname           => 'database-1.czaaygccsncp.ap-northeast-2.rds.amazonaws.com',
+    port               => 5432,
+    service_name       => 'postgres',
+    credential_name    => 'HMM_RDS_PG_CRED',
+    ssl_server_cert_dn => NULL,
+    private_target     => FALSE,
+    gateway_params     => JSON_OBJECT('db_type' VALUE 'postgres')
+  );
+END;
+/
+
+SELECT db_link, username, host, created
+FROM user_db_links
+WHERE db_link = 'HMM_RDS_PG_LINK';