Automattic\WooCommerce\Internal\Utilities

DatabaseUtil::get_max_index_length │ public │ WC 1.0

Get max index length.

Method of the class: DatabaseUtil{}

Returns

Int. Max index length.

Usage

$DatabaseUtil = new DatabaseUtil();
$DatabaseUtil->get_max_index_length(): int;

DatabaseUtil::get_max_index_length() DatabaseUtil::get max index length code ^{WC 10.3.6}

public function get_max_index_length(): int {
	/**
	 * Filters the maximum index length in the database.
	 *
	 * Indexes have a maximum size of 767 bytes. Historically, we haven't need to be concerned about that.
	 * As of WP 4.2, however, they moved to utf8mb4, which uses 4 bytes per character. This means that an index which
	 * used to have room for floor(767/3) = 255 characters, now only has room for floor(767/4) = 191 characters.
	 *
	 * Additionally, MyISAM engine also limits the index size to 1000 bytes. We add this filter so that interested folks on InnoDB engine can increase the size till allowed 3071 bytes.
	 *
	 * @param int $max_index_length Maximum index length. Default 191.
	 *
	 * @since 8.0.0
	 */
	$max_index_length = apply_filters( 'woocommerce_database_max_index_length', 191 );
	// Index length cannot be more than 768, which is 3078 bytes in utf8mb4 and max allowed by InnoDB engine.
	return min( absint( $max_index_length ), 767 );
}