From dca4125b2b5e6a7416f009384956125ca84030e3 Mon Sep 17 00:00:00 2001
From: Ziaratban <abolfazl.ziaratban@gmail.com>
Date: Sat, 15 Feb 2020 01:08:40 +0330
Subject: [PATCH 1/2] Update Query.php

---
 src/Query.php | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/Query.php b/src/Query.php
index f1a8c2386..5dc0c1acc 100644
--- a/src/Query.php
+++ b/src/Query.php
@@ -495,7 +495,24 @@ public function exists($db = null)
         if (!empty($this->emulateExecution)) {
             return false;
         }
+
+        #better performance
+        #save last options
+        $tmpOrderBy = $this->orderBy;
+        $tmpLimit = $this->limit;
+        $tmpOffset = $this->offset;
+        $tmpSelect = $this->select;
+        $this->orderBy = [];
+        $this->limit = 1;
+        $this->offset = null;
+        $this->select = ['_id'];
         $cursor = $this->buildCursor($db);
+        #return last options
+        $this->orderBy = $tmpOrderBy;
+        $this->limit = $tmpLimit;
+        $this->offset = $tmpOffset;
+        $this->select = $tmpSelect;
+
         foreach ($cursor as $row) {
             return true;
         }

From 633ed7385011b9c6c448ee91ae2eddef21ca467d Mon Sep 17 00:00:00 2001
From: Ziaratban <abolfazl.ziaratban@gmail.com>
Date: Tue, 25 Feb 2020 10:42:10 +0330
Subject: [PATCH 2/2] Update Query.php

---
 src/Query.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/Query.php b/src/Query.php
index 5dc0c1acc..95c686393 100644
--- a/src/Query.php
+++ b/src/Query.php
@@ -496,7 +496,11 @@ public function exists($db = null)
             return false;
         }
 
-        #better performance
+        /**
+         * better performance
+         * please read this article : Checking if a document exists – MongoDB slow findOne vs find
+         * https://blog.serverdensity.com/checking-if-a-document-exists-mongodb-slow-findone-vs-find/
+         */
         #save last options
         $tmpOrderBy = $this->orderBy;
         $tmpLimit = $this->limit;