From 8b1efe58d24f16764af5e7164d54073b61d6d7ae Mon Sep 17 00:00:00 2001
From: Ziaratban <abolfazl.ziaratban@gmail.com>
Date: Fri, 27 Dec 2019 19:18:54 +0330
Subject: [PATCH] better performance for exists() method of Query class

https://github.com/yiisoft/yii2-mongodb/issues/290
---
 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;
         }