On Tue, Sep 21, 2010 at 10:58 PM, Pei He <hepeimail@gmail.com> wrote:
> Hi Tom,
> The bitmapset works for me.
>
> I want to implement the operator for the following query:
>
> Select * from a left join b on a.id = b.id order by b.id;
>
> In a left outer join, I want the tuples that have matches in the inner table
> appear first. So, the order by clause is need.
Why can't you just write SELECT * FROM a LEFT JOIN b ON a.id = b.id
ORDER BY b.id NULLS FIRST? "I want my query results in a different
order" is almost never something that requires modifying the source
code.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company