| From: | Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> |
|---|---|
| To: | josh(at)agliodbs(dot)com |
| Cc: | sqllist <pgsql-sql(at)postgresql(dot)org> |
| Subject: | Re: Weird NOT IN effect with NULL values |
| Date: | 2001-03-01 20:46:11 |
| Message-ID: | 200103012046.PAA19437@candle.pha.pa.us |
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| Lists: | pgsql-sql |
> SELECT name
> FROM customer
> WHERE NOT EXISTS (
> SELECT customer_id
> FROM salesorder
> WHERE customer_id = customer.customer_id
> );
>
> Bruce, you may want to consider editing your next edition to include the
> above modification. WHERE ... NOT IN is a bad idea for any subselect on
> medium-large tables.
FAQ item mentions this, and section 8.2 shows eqivalency at the end of
the section.
--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
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