Only necessary to do flush during cursor - closes #736

Author: porsager

src/connection.js

@@ -956,14 +956,14 @@ function Connection(options, queues = {}, { onopen = noop, onend = noop, onclose
   function Execute(portal = '', rows = 0) {
     return Buffer.concat([
       b().E().str(portal + b.N).i32(rows).end(),
-      Flush
+      rows === 0 ? Sync : Flush
     ])
   }
 
   function Close(portal = '') {
     return Buffer.concat([
       b().C().str('P').str(portal + b.N).end(),
-      b().S().end()
+      Sync
     ])
   }