"Stephan Szabo" <sszabo@kick.com> writes:
>> I had not seen those statements before; I have been mistakenly modifying
>> 6.5.3 sources, not 7.0.2. I will incorporate them in my work. Is there any
>> way of also disabling all constraint checking while loading the data?
> Well, for unique you could remove/recreate the unique index. NOT NULL
> is probably not worth bothering with. Check constraints might be able
> to be turned off for a table by setting relchecks to 0 in the pg_class
> row and the resetting it after data is loaded (sort of like what we do
> on data only dumps for triggers).
There's no need to disable NOT NULL, nor unique constraints either,
since those are purely local to a table --- if they're going to fail,
altering load order doesn't prevent it. The things you need to worry
about are constraint expressions that cause references to other tables
(perhaps indirectly via a function).
If we had ALTER TABLE ADD CONSTRAINT then the problem would be largely
solved, I believe. This should be a minor exercise --- the heavy
lifting is already done, because heap.c's AddRelationRawConstraints()
is already set up to be invokable on a pre-existing relation. Also
the parser knows how to parse ALTER TABLE ADD CONSTRAINT ... I think
all that's missing is a few lines of glue code in command.c.
regards, tom lane
