Обсуждение: An alternatives to rules and triggers

Is there some way that one can determine whether a table has changed
i.e. an insert, delete, update, without having to resort to setting a
flag in another table using a triger or rule.

I was wondering whether one of the system relations keep track of
whether a table has been modifed.

Glen Eustace <geustace@godzone.net.nz> writes:
> I was wondering whether one of the system relations keep track of
> whether a table has been modifed.

Nope.

            regards, tom lane

Glen Eustace wrote:
> Is there some way that one can determine whether a table has changed
> i.e. an insert, delete, update, without having to resort to setting a
> flag in another table using a triger or rule.
>
> I was wondering whether one of the system relations keep track of
> whether a table has been modifed.
>

How soon do you need to know that a change has occured? I suppose one
could monitor the log. You'd want to keep track of where in the log your
script read up to the last time, in order to avoid having to run through
from the beginning each time.

And you'd want to ensure that you scan the log right before it's
rotated, of course.

A bit of a hack ...

b

On Sat, May 05, 2007 at 03:01:36PM +1200, Glen Eustace wrote:

> Is there some way that one can determine whether a table has changed
> i.e. an insert, delete, update, without having to resort to setting a
> flag in another table using a triger or rule.
You can NOTIFY a LISTENing client which does involve a
trigger but does not require another table holding flags
or such.

Karsten
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