Deprecated function: session_set_save_handler(): Providing individual callbacks instead of an object implementing SessionHandlerInterface is deprecated in drupal_session_initialize() (line 245 of includes/session.inc).
Deprecated function: Creation of dynamic property alpha_theme_container::$delta is deprecated in alpha_theme_container->__construct() (line 25 of sites/all/themes/contrib/omega/alpha/includes/base.inc).
Improved InnoDB fast index creation - MySQL Performance Blog
By temporarily dropping secondary indexes from the new table before copying the data, and then recreating them later, ALTER TABLE can take advantage of the fast index creation feature even when it has to copy the entire table.