Re: RI triggers and schemas - Mailing list pgsql-hackers

From Jan Wieck
Subject Re: RI triggers and schemas
Date
Msg-id 200204011525.g31FP3J29713@saturn.janwieck.net
Whole thread Raw
In response to Re: RI triggers and schemas  (Christopher Kings-Lynne <chriskl@familyhealth.com.au>)
Responses Re: RI triggers and schemas  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Christopher Kings-Lynne wrote:
> > I've just realized that if we change the RI trigger arguments this way,
> > we will have a really serious problem with accepting pg_dump scripts
> > from prior versions.  The scripts' representation of foreign key
> > constraints will contain commands like
> >
> > CREATE CONSTRAINT TRIGGER "<unnamed>" AFTER UPDATE ON "bar"  FROM "baz" NOT DEFERRABLE INITIALLY IMMEDIATE FOR EACH
ROWEXECUTE PROCEDURE "RI_FKey_noaction_upd" ('<unnamed>', 'baz', 'bar', 'UNSPECIFIED', 'f1', 'f1');
 
> >
> > which will absolutely not work at all if the 7.3 triggers are expecting
> > to find OIDs in those arguments.
>
> Why can't we just hack up the CREATE CONSTRAINT TRIGGER code to look up
> the OIDs, etc. for the arguments and convert them internally to an ALTER
> TABLE/ADD CONSTRAINT or whatever...
   And  what  language  hack  do  you  suggest  to  suppress the   complete referential check of the foreign key table
at ALTER   TABLE  ...  time? Currently, it does a sequential scan of the   entire  table  to  check  every  single
row. So  adding   3   constraints to a 10M row table might take some time.
 
   Note,  that  that language hack will again make the dump non-   ANSI complient and thus, I don't consider the
entire change   to ALTER TABLE an improvement at all.
 


Jan

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