On Fri, Feb 29, 2008 at 02:53:05PM +0530, Gurjeet Singh wrote:
> In my opinion (without looking at the code), if you have a grouping-function
> or ORDER BY or GROUP BY clause, then yes, the whole query has to be executed
> to show the first row of the result-set. But if the query doesn't have any
> of these clauses, then the DB has the ability to send back the first row
> from the result as soon as it processes it (i.e after WHERE clause
> processing), and stop the query execution there.
Except if you have an index on the column you're ordering by. Then the
server can really return the first row quickly.
Have a nice day,
--
Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/
> Those who make peaceful revolution impossible will make violent revolution inevitable.
> -- John F Kennedy
