diff --git a/public/roadmap-content/postgresql-dba.json b/public/roadmap-content/postgresql-dba.json
index 9babb7e3e..2b88101fc 100644
--- a/public/roadmap-content/postgresql-dba.json
+++ b/public/roadmap-content/postgresql-dba.json
@@ -451,7 +451,7 @@
       },
       {
         "title": "Query Processing in PostgreSQL",
-        "url": "https://medium.com/agedb/query-processing-in-postgresql-1309fa93f69f",
+        "url": "https://www.interdb.jp/pg/pgsql03.html",
         "type": "article"
       }
     ]