From 2eae60ab68f0867d0c761055fc8ef9bf4b982646 Mon Sep 17 00:00:00 2001
From: Brendan Long <self@brendanlong.com>
Date: Fri, 26 Oct 2018 13:37:44 -0400
Subject: [PATCH]  Use a `Query` message for parameterless `execute`s

`execute` uses a significantly more complicated protocol (parse, prepare,
execute) and we should avoid that overhead if we don't actually need
parameters.

I didn't do this with execute_iter or execute_fold because the
simple_query interface doesn't have those versions yet.
---
 pgx/src/pgx.ml | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/pgx/src/pgx.ml b/pgx/src/pgx.ml
index d9573c9..2581492 100644
--- a/pgx/src/pgx.ml
+++ b/pgx/src/pgx.ml
@@ -1325,7 +1325,17 @@ module Make (Thread : IO) = struct
         simple_query' dbh query)
 
   let execute ?(params=[]) db query =
-    Prepared.(with_prepare db ~query ~f:(fun s ->
+    match params with
+    | [] ->
+      simple_query db query
+      >>| (function
+        | rows :: [] -> rows
+        | results ->
+          fail_msg "Pgx.execute: Query returned %d result sets but \
+                    execute should only ever return one. Query was: %s"
+            (List.length results) query)
+    | _ ->
+      Prepared.(with_prepare db ~query ~f:(fun s ->
         execute s ~params))
 
   let execute_iter ?(params=[]) db query ~f =