Re: [Q] Update from a table

Ladislav Lenart <lenartlad@volny.cz> writes:
> What happens if I issue UPDATE SET FROM... but with incomplete/buggy WHERE
> condition and thus SEVERAL rows from the from_list match ONE row to update?

Any given row will be updated at most once.  However, the from_list row
it gets updated against will be unpredictable, depending on the
implementation of the join.

            regards, tom lane