Improve last token native price sql query (#3269)

crates/orderbook/src/database/orders.rs

@@ -493,39 +493,48 @@ impl Postgres {
     }
 
     pub async fn token_metadata(&self, token: &H160) -> Result<TokenMetadata> {
-        let timer = super::Metrics::get()
-            .database_queries
-            .with_label_values(&["token_first_trade_block"])
-            .start_timer();
-
-        let (first_trade_block, native_price) = tokio::try_join!(
-            async {
+        let (first_trade_block, native_price): (Option<u32>, Option<U256>) = tokio::try_join!(
+            self.execute_instrumented("token_first_trade_block", async {
                 let mut ex = self.pool.acquire().await?;
                 database::trades::token_first_trade_block(&mut ex, ByteArray(token.0))
                     .await
                     .map_err(anyhow::Error::from)?
                     .map(u32::try_from)
                     .transpose()
                     .map_err(anyhow::Error::from)
-            },
-            async {
+            }),
+            self.execute_instrumented("fetch_latest_token_price", async {
                 let mut ex = self.pool.acquire().await?;
-                Ok::<Option<U256>, anyhow::Error>(
+                Ok(
                     database::auction_prices::fetch_latest_token_price(&mut ex, ByteArray(token.0))
                         .await
                         .map_err(anyhow::Error::from)?
                         .and_then(|price| big_decimal_to_u256(&price)),
                 )
-            }
+            })
         )?;
 
-        timer.stop_and_record();
-
         Ok(TokenMetadata {
             first_trade_block,
             native_price,
         })
     }
+
+    async fn execute_instrumented<F, T>(&self, label: &str, f: F) -> Result<T>
+    where
+        F: std::future::Future<Output = Result<T>>,
+    {
+        let timer = super::Metrics::get()
+            .database_queries
+            .with_label_values(&[label])
+            .start_timer();
+
+        let result = f.await?;
+
+        timer.observe_duration();
+
+        Ok(result)
+    }
 }
 
 #[async_trait]

database/sql/V079__auction_prices_token_index.sql

@@ -0,0 +1,2 @@
+-- Create index to improve `fetch_latest_token_price` query performance.
+CREATE INDEX auction_prices_token_auction_id_idx ON auction_prices (token, auction_id DESC);