Robert Haas <robertmhaas@gmail.com> writes:
> On Wed, Oct 19, 2011 at 12:42 PM, Greg Jaskiewicz <gryzman@gmail.com> wrote:
>> When I do an insert on table B, the database check if value for column
>> �table_a_id� exists in table A
>> But, if I do an update of column �address� of table B, does the database
>> check again?
> I just tested this, and it seems not.
It will not, unless you update the same row more than once in a single
transaction. If you do that, it no longer has enough information to be
sure the referencing value hasn't changed in that transaction, so it
will do a check.
regards, tom lane