> Suppose I have vacuum_values() function, which removes all
> "no longer referenced" by parent column. Kind of function
> to be run from time to time to clean table from crud.
> It looks like this:
I suppose you have a good reason to not use a foreign key with "ON DELETE
CASCADE" ?
> FOR r IN SELECT value_id FROM values NATURAL LEFT JOIN
> other_tab WHERE other_tab.value_id IS NULL FOR UPDATE OF values LOOP
> DELETE FROM values WHERE value_id = r.value_id;
> END LOOP;
> RETURN;
I don't remember the exact syntax (look in the DELETE docs) but you can
certainly put a left join inside a delete and do it all at once with only
one query, and it'll be faster to boot.