2009/10/5 Matthew Wakeling <matthew(at)flymine(dot)org>
>
> Yes, that does work, but only because id is NOT NULL. I thought Postgres
> 8.4 had had a load of these join types unified to make it less important how
> the query is written?
>
well, as a rule of thumb - unless you can't think of a default value of
column - don't use nulls. So using nulls as default 'idunno' - is a bad
practice, but everybody's opinion on that differ.
But back on a subject, postgresql is very very poor performance wise with
[NOT] IN () type of constructs. So if you can, avoid them, and learn to use
joins.
--
GJ