On Fri, Feb 29, 2008 at 3:55 PM, Martijn van Oosterhout <[EMAIL PROTECTED]> wrote:
> 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. Quickly for sure... but I don't think 'without processing all the rows that qualify'. I think it will still process all the rows and return just one. Best regards, -- [EMAIL PROTECTED] [EMAIL PROTECTED] gmail | hotmail | indiatimes | yahoo }.com EnterpriseDB http://www.enterprisedb.com 17° 29' 34.37"N, 78° 30' 59.76"E - Hyderabad 18° 32' 57.25"N, 73° 56' 25.42"E - Pune * 37° 47' 19.72"N, 122° 24' 1.69" W - San Francisco http://gurjeet.frihost.net Mail sent from my BlackLaptop device
