magento-test/app/code/Magento/CatalogSearch/etc/adminhtml/system.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Config:etc/system_file.xsd">
    <system>
        <section id="catalog">
            <group id="seo">
                <field id="search_terms" translate="label" type="select" sortOrder="1" showInDefault="1" showInWebsite="1" showInStore="1" canRestore="1">
                    <label>Popular Search Terms</label>
                    <source_model>Magento\Config\Model\Config\Source\Enabledisable</source_model>
                </field>
            </group>
            <group id="search" translate="label" type="text" sortOrder="500" showInDefault="1" showInWebsite="1" showInStore="1">
                <label>Catalog Search</label>
                <field id="engine" canRestore="1">
                    <backend_model>Magento\CatalogSearch\Model\Adminhtml\System\Config\Backend\Engine</backend_model>
                    <comment>If not specified, Default Search Engine will be used.</comment>
                </field>
                <field id="min_query_length" translate="label comment" type="text" sortOrder="5" showInDefault="1" showInWebsite="1" showInStore="1" canRestore="1">
                    <label>Minimal Query Length</label>
                    <validate>validate-digits</validate>
                    <comment>This value must be compatible with the corresponding setting in the configured search engine. Be aware: a low query length limit may cause the performance impact.</comment>
                </field>
                <field id="max_query_length" translate="label comment" type="text" sortOrder="10" showInDefault="1" showInWebsite="1" showInStore="1" canRestore="1">
                    <label>Maximum Query Length</label>
                    <validate>validate-digits</validate>
                    <comment>This value must be compatible with the corresponding setting in the configured search engine.</comment>
                </field>
                <field id="max_count_cacheable_search_terms" translate="label comment" type="text" sortOrder="10" showInDefault="1" showInWebsite="1" showInStore="1" canRestore="1">
                    <label>Number of top search results to cache</label>
                    <comment>Number of popular search terms to be cached for faster response. Use “0” to cache all results after a term is searched for the second time.</comment>
                    <validate>validate-digits</validate>
                </field>
                <field id="autocomplete_limit" translate="label" type="text" sortOrder="19" showInDefault="1" showInWebsite="1" showInStore="1" canRestore="1">
                    <label>Autocomplete Limit</label>
                    <validate>validate-digits</validate>
                </field>
                <field id="enable_eav_indexer" translate="label" type="select" sortOrder="18" showInDefault="1" canRestore="1">
                    <label>Enable EAV Indexer</label>
                    <comment>Enable/Disable Product EAV indexer to improve indexation speed. Make sure that indexer is not used by 3rd party extensions.</comment>
                    <depends>
                        <field id="engine" separator="," negative="1">mysql</field>
                    </depends>
                    <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>
                </field>
            </group>
        </section>
    </system>
</config>