[PERFORMANCE] Added index to the experius_page_not_found

 This will reduce the load time of a 404 (in a case it was from 3.6s to 329ms)

Setup/UpgradeSchema.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Experius\PageNotFound\Setup;
+
+use Magento\Framework\DB\Adapter\AdapterInterface;
+use Magento\Framework\Setup\UpgradeSchemaInterface;
+use Magento\Framework\Setup\ModuleContextInterface;
+use Magento\Framework\Setup\SchemaSetupInterface;
+
+class UpgradeSchema implements UpgradeSchemaInterface
+{
+
+    /**
+     * {@inheritdoc}
+     */
+    public function upgrade(
+        SchemaSetupInterface $setup,
+        ModuleContextInterface $context
+    ) {
+        $setup->startSetup();
+        if (version_compare($context->getVersion(), "1.0.2", "<")) {
+            $this->addIndexesToTables($setup);
+        }
+        $setup->endSetup();
+    }
+
+    public function addIndexesToTables($setup)
+    {
+        $setup->getConnection()->query("ALTER TABLE `{$setup->getTable('experius_page_not_found')}` ADD INDEX `EXPERIUS_PAGE_NOT_FOUND_FROM_URL` (`from_url`(255));");
+    }
+}

etc/module.xml

@@ -1,4 +1,4 @@
 <?xml version="1.0" ?>
 <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
-	<module name="Experius_PageNotFound" setup_version="1.0.1"/>
+	<module name="Experius_PageNotFound" setup_version="1.0.2"/>
 </config>