PHP script to recreate the mg3_catalogsearch_fulltext_scope1 table for Magento 2.

magento2_recreate_catalogsearch.php

<?php

try {
    require __DIR__ . '/app/bootstrap.php';
} catch (\Exception $e) {
    echo $e->getMessage();
    exit(1);
}

$bootstrap = \Magento\Framework\App\Bootstrap::create(BP, $_SERVER);
$app = $bootstrap->createApplication('Magento\Framework\App\Http');

echo 'Startup complete.' . '<br/>';

$indexerHandlerFactory = \Magento\Framework\App\ObjectManager::getInstance()->get("Magento\\CatalogSearch\\Model\\Indexer\\IndexerHandlerFactory");
$indexerConfig = \Magento\Framework\App\ObjectManager::getInstance()->get("Magento\\Framework\\Indexer\\ConfigInterface");
$dimensionFactory = \Magento\Framework\App\ObjectManager::getInstance()->get("Magento\\Framework\\Search\\Request\\DimensionFactory");

try {
    $dimensions = [
        $dimensionFactory->create(['name' => 'scope', 'value' => 'default'])
    ];
    $configData = $indexerConfig->getIndexer('catalogsearch_fulltext');
    $indexHandler = $indexerHandlerFactory->create(['data' => $configData]);
    $indexHandler->cleanIndex($dimensions);
} catch(Exception $e) {
    echo 'Error recreating catalogsearch_fulltext<br/>';
    print($e->getMessage());
}

echo '<br/>';
echo "Successfully recreated catalogsearch_fulltext<br/>";

$indexerFactory = \Magento\Framework\App\ObjectManager::getInstance()->get("Magento\Indexer\Model\IndexerFactory");
$indexerIds = array(
    'catalog_category_product',
    'catalog_product_category',
    'catalog_product_price',
    'catalog_product_attribute',
    'cataloginventory_stock',
    'catalogrule_product',
    'catalogsearch_fulltext',
);
foreach ($indexerIds as $indexerId) {
    try {
        echo " create index: ".$indexerId."\n";
        $indexer = $indexerFactory->create();
        $indexer->load($indexerId);
        $indexer->reindexAll();

    } catch (\Exception $e) {
        echo 'Error reindexing ' . $indexerId . '<br/>';
        echo $e->getMessage();
        echo "<br/>";
    }
}

echo "<br/>";
echo "Done";

?>