wp_start_object_cache

		'active'           => '%d',
		'cat_id'           => '%d',
		'deleted'          => '%d',
		'lang_id'          => '%d',
		'mature'           => '%d',
		'public'           => '%d',
		'site_id'          => '%d',
		'spam'             => '%d',
	);

	$prefix = $wpdb->set_prefix( $table_prefix );

	if ( is_wp_error( $prefix ) ) {
		wp_load_translations_early();
		wp_die(
			sprintf(
				/* translators: 1: $table_prefix, 2: wp-config.php */
				__( '<strong>Error</strong>: %1$s in %2$s can only contain numbers, letters, and underscores.' ),
				'<code>$table_prefix</code>',
				'<code>wp-config.php</code>'
			)
		);
	}
}

/**
 * Toggle `$_wp_using_ext_object_cache` on and off without directly
 * touching global.
 *
 * @since 3.7.0
 *
 * @global bool $_wp_using_ext_object_cache
 *
 * @param bool $using Whether external object cache is being used.
 * @return bool The current 'using' setting.
 */
function wp_using_ext_object_cache( $using = null ) {
	global $_wp_using_ext_object_cache;
	$current_using = $_wp_using_ext_object_cache;
	if ( null !== $using ) {
		$_wp_using_ext_object_cache = $using;
	}
	return $current_using;
}

/**
 * Start the WordPress object cache.
 *
 * If an object-cache.php file exists in the wp-content directory,
 * it uses that drop-in as an external object cache.
 *
 * @since 3.0.0
 * @access private
 *
 * @global array $wp_filter Stores all of the filters.
 */
function wp_start_object_cache() {
	global $wp_filter;
	static $first_init = true;