Batch query packets to avoid additional latency

packages/pg/lib/connection.js

@@ -152,6 +152,44 @@ class Connection extends EventEmitter {
     this._send(serialize.query(text))
   }
 
+  // query using single batch of packets
+  // https://github.com/brianc/node-postgres/issues/3325
+  queryWithPacketBatching(query, valueMapper) {
+    const packets = []
+
+    if (!query.hasBeenParsed(this)) {
+      packets.push(serialize.parse({
+        text: query.text,
+        name: query.name,
+        types: query.types,
+      }))
+    }
+
+    packets.push(serialize.bind({
+      portal: query.portal,
+      statement: query.name,
+      values: query.values,
+      binary: query.binary,
+      valueMapper: valueMapper,
+    }))
+
+    packets.push(serialize.describe({
+      type: 'P',
+      name: query.portal || '',
+    }))
+
+    packets.push(serialize.execute({
+      portal: query.portal,
+      rows: query.rows,
+    }))
+
+    if (!query.rows) {
+      packets.push(syncBuffer)
+    }
+
+    this._send(Buffer.concat(packets))
+  }
+
   // send parse message
   parse(query) {
     this._send(serialize.parse(query))

packages/pg/lib/query.js

@@ -161,7 +161,7 @@ class Query extends EventEmitter {
       return new Error('Query values must be an array')
     }
     if (this.requiresPreparation()) {
-      this.prepare(connection)
+      connection.queryWithPacketBatching(this, utils.prepareValue)
     } else {
       connection.query(this.text)
     }