Обсуждение: System catalogs

I saw in the docs that you are not supposed to edit them manually... However is it considered appropriate to do other
thingssuch as:
 

referencing them (adding foreign keys on them)
adding triggers to them (e.g. delete all this stuff if this table is dropped). This would include adding cascade
clausesto the referring.
 

Regards,

Aasmund Midttun Godal

aasmund@godal.com - http://www.godal.com/
+47 40 45 20 46

On Sun, 18 Nov 2001, Aasmund Midttun Godal wrote:

> I saw in the docs that you are not supposed to edit them manually...
> However is it considered appropriate to do other things such as:
>
> referencing them (adding foreign keys on them)
> adding triggers to them (e.g. delete all this stuff if this table is
> dropped). This would include adding cascade clauses to the referring.

Generally I don't think so.  What were you trying to like with foreign
keys?

"Aasmund Midttun Godal" <postgresql@envisity.com> writes:
> I saw in the docs that you are not supposed to edit them manually... However is it considered appropriate to do other
thingssuch as:
 
> referencing them (adding foreign keys on them)
> adding triggers to them (e.g. delete all this stuff if this table is dropped). This would include adding cascade
clausesto the referring.
 

By and large, triggers on system catalogs will not work, because most
of the internal manipulations of the catalogs do not bother to fire
triggers.  This implies that foreign key constraints won't work either,
since those are implemented by triggers.
        regards, tom lane