[viz]: improve fortunes in pg case (#8524)

frameworks/Rust/viz/src/db_pg.rs

@@ -160,21 +160,25 @@ impl PgConnection {
     }
 
     pub async fn tell_fortune(&self) -> Result<Vec<Fortune>, PgError> {
-        let mut items = self
+        let mut items = vec![Fortune {
+            id: 0,
+            message: Cow::Borrowed("Additional fortune added at request time."),
+        }];
+
+        let stream = self
             .client
-            .query(&self.fortune, &[])
-            .await?
-            .iter()
-            .map(|row| Fortune {
+            .query_raw::<_, _, &[i32; 0]>(&self.fortune, &[])
+            .await?;
+        pin!(stream);
+
+        while let Some(row) = stream.next().await {
+            let row = row?;
+
+            items.push(Fortune {
                 id: row.get(0),
                 message: Cow::Owned(row.get(1)),
-            })
-            .collect::<Vec<_>>();
-
-        items.push(Fortune {
-            id: 0,
-            message: Cow::Borrowed("Additional fortune added at request time."),
-        });
+            });
+        }
 
         items.sort_by(|it, next| it.message.cmp(&next.message));