Re: LIMIT Question

On Fri, Feb 29, 2008 at 3:55 PM, Martijn van Oosterhout <kleptog(at)svana(dot)org>
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,
--
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