Martijn Tonies wrote:

>
> News for you :-)
>
> If you add a required column (not NULL) to a table with existing data,
> and include a default for that column, you'll get this behaviour.
>

Yes, this is a workaround to avoid unrestorable backup in case of NULLs
in NOT NULL column. But it seems that it raised more problems than
solved. One more example - if NOW is used in timestamp column, current
date/time is always selected form it. And when your restore from a
backup, you get the date, when backup was doen, in that columns.