Postgres guide with backup role section

Guides/postgres.md

@@ -0,0 +1,14 @@
+# Postgres SQL
+
+Tips for using Postgres SQL.
+
+## Backup
+
+Create backup profile :
+
+```
+CREATE ROLE backup WITH 
+    NOSUPERUSER
+    NOCREATEDB
+    NOCREATEROLE ;
+```