Thread: Error with views containing sub-queries with distinct

Last night I just upgraded to a nightly snapshot of 7.4 and noticed an 
error on queries that had previously worked (in version 7.3.x and 
previous 7.4's snapshots up to about a month old).

I have a view that I can distill into a base case of:

CREATE VIEW testing_v AS    SELECT table_a.*    FROM table_a    WHERE    (table_a.some_id IN (        SELECT DISTINCT
table_b.some_id       FROM table_b    ));
 

When I do :

select * from testing_v;

I get:

JOIN qualification may not refer to other relations

I have found that if I remove the distinct on the sub-query, it behaves 
as expected.

Yes, I know the distinct is probably useless but we are in the process 
of porting it to postgres and have lots of cleanup left.

We are migrating from a commercial database (and paid good money) and 
found postgres to be a joy (substantially fast, less gotchas, better at 
embeding business logic at db level).

Thank you very much.  I appreciate all the effort that has put into such 
a great product.

                        --spt



PS:  Please cc me as I am not on list.

"Sean P. Thomas" <spt@ulanji.com> writes:
> I get:
> JOIN qualification may not refer to other relations

Problem confirmed here, will look into it.  I have a feeling this is a
bad side-effect of this patch:

2003-10-13 19:48  tgl
* src/backend/optimizer/prep/prepjointree.c: pull_up_subqueries()should copy the subquery before starting to modify it.
  Not surewhy I'd thought it would be a good idea to do differently way backwhen, but Greg Stark exposed the folly of
doingso ...
 

but I don't see why as yet.
        regards, tom lane

"Sean P. Thomas" <spt@ulanji.com> writes:
> Last night I just upgraded to a nightly snapshot of 7.4 and noticed an 
> error on queries that had previously worked (in version 7.3.x and 
> previous 7.4's snapshots up to about a month old).

Fixed, thanks for the test case.
        regards, tom lane