Re: RI oddness

Jan Wieck <JanWieck@Yahoo.com> writes:
>     What'd be easy is this:

>     -   We already have two entry points for INSERT/UPDATE on  FK
>         table, but the one for UPDATE is fortunately unused.

>     -   We  change  analyze.c  to  install  the RI_FKey_check_upd
>         trigger if the constraint has an ON  DELETE  SET  DEFAULT
>         clause.  Otherwise  it  uses RI_FKey_check_ins as it does
>         now.

Unfortunately, such a fix really isn't going to fly as a patch release.
Not only does it not work for existing tables, but it won't work for
tables created by dump and reload from a prior version (since they
won't have the right set of triggers ... another illustration of why
the lack of an abstract representation of the RI constraints was a
Bad Move).  In fact I'm afraid that your proposed change would actively
break tables imported from a prior version; wouldn't RI_FKey_check_ins
do the wrong thing if applied as an update trigger?

>     I  think  the  usage  of ON DELETE SET DEFAULT is a very rare
>     case out in the field. Thus the  dump/reload  requirement  is
>     limited  to  a small number of databases (if any).

But dump/reload won't fix the tables' triggers.

Given that ON DELETE SET DEFAULT isn't used much, I think we should
not waste time creating an incomplete hack solution for 7.1.*, but
just write it off as a known bug and move forward with a real solution
for 7.2.
        regards, tom lane