Re: Preserving order through an inner join

Gurjeet Singh wrote:
> On Sun, Sep 26, 2010 at 9:37 PM, Tom Lane  wrote:
> 
>     The SQL standard explicitly disavows any particular
>     output row order unless there is a top-level ORDER BY.  (In fact,
>     unless things have changed recently an ORDER BY in a sub-select isn't
>     even legal per spec.)
> 
> Not sure about the SQL spec allowing it, but an ORDER BY followed by a 
> LIMIT does have valid use cases in sub-selects.

Absolutely it does, but that is just a row *filtering* operation.  You still 
have to have a separate ORDER BY in the outermost query to get result rows 
output in a particular order. -- Darren Duncan