We are storing everywhere PRTime value, those are taking up much more space than what we need, especially cause many of those columns are indexed, so they take double space. For the purpose of history we don't need microseconds precision, let alone the fact timers may have very low resolution, like 16ms. Unfortunately while this would save some precious db space, it is also definitely not backwards compatible (even if we could detect and fix bogus times on downgrade/upgrade by detecting times in future)