David Durham wrote:

> Christopher Browne wrote:
>
>> No, there is no support, as triggers do not fire when these kinds of
>> tuples are altered.
>
>
> So no trigger is fired when a row with an Oid field is
> inserted/updated/...?  Or is just the particular Oid field that
> doesn't fire any triggers?
>
> Thanks,
>
> Dave

The trouble is with the lo_ functions.

The manipulations of BLOBs involve using functions like lo_import(),
lo_export(), lo_read(), lo_write().

No triggers are fired when those manipulations take place, so there's
not a good way to detect that they have changed and need to be copied
around.