Re: [SQL] subqueries

On Tue, 13 Apr 1999, Tom Lane wrote:

> Walt Bigelow <walt@stimpy.com> writes:
> > SELECT agencyid, first, last 
> > FROM tbladdress
> > WHERE type = 1
> > AND agencyid NOT IN
> > 	(SELECT distinct agencylink
> > 	FROM tbladdress 
> > 	WHERE type = 2)
> > ORDER BY last;
> 
> Looks reasonable ...
> 
> > This query returns 0 rows [ when it shouldn't ].
> 
> Sounds like a bug.  What version of Postgres are you running?
> What do you get from "EXPLAIN"ing that query?  What are the
> data types of the columns being used?
> 

Tom,

I am using postgres 6.4.2 on a RH5.1 SMP box.

The output of explain:
NOTICE: QUERY PLAN:

Seq Scan on tbladdress  (cost=50.34 size=348 width=24)
  SubPlan
    ->  Unique  (cost=50.34 size=0 width=0)
          -> Sort  (cost=50.34 size=0 width=0)
               ->  Seq Scan on tbladdress  (cost=50.34 size=348 width=4)

EXPLAIN

The data types are int4 for both agencyid and agencylink.  And there are
about 800 rows total of 5 different types.  (the type field is int4 as
well)

Thanks again,
Walt