PHWinfo - Afficher un message - Re: adding LIMIT 1 to improve performance?

21/09/2007, 05h59

On Sep 20, 3:31 am, "Martijn Tonies" <m.ton...@upscene.removethis.com>
wrote:
> > > Before you do, what makes you think that adding LIMIT 1 to a
> > > statement that searches the rows to modify by PRIMARY KEY!!
> > > value would become any faster?
>
> > as I said, I noticed phpmyadmin does that, so I got this doubt and
> > asked here (since it's not mentioned in the docs, AFAIK)
>
> It's probably just a standard thing PHPMyAdmin does for all table
> updates, even the ones without a PK, to ensure only 1 row gets
> updated.
>
> --
> Martijn Tonies
> Database Workbench - tool for InterBase, Firebird, MySQL, NexusDB, Oracle &
> MS SQL Server
> Upscene Productionshttp://www.upscene.com
> My thoughts:http://blog.upscene.com/martijn/
> Database development questions? Check the forum!http://www.databasedevelopmentforum.com

As a force of habit, I tend to do limit x (usually 1) if I'm executing
an update or a delete simply for the fact that I might accidentally
create a sql statement that modifies more items than I wanted to by
accident. Just a thought.

21/09/2007, 05h59	#7
Aaron Saray Messages: n/a Hébergeur:	Re: adding LIMIT 1 to improve performance? On Sep 20, 3:31 am, "Martijn Tonies" <m.ton...@upscene.removethis.com> wrote: > > > Before you do, what makes you think that adding LIMIT 1 to a > > > statement that searches the rows to modify by PRIMARY KEY!! > > > value would become any faster? > > > as I said, I noticed phpmyadmin does that, so I got this doubt and > > asked here (since it's not mentioned in the docs, AFAIK) > > It's probably just a standard thing PHPMyAdmin does for all table > updates, even the ones without a PK, to ensure only 1 row gets > updated. > > -- > Martijn Tonies > Database Workbench - tool for InterBase, Firebird, MySQL, NexusDB, Oracle & > MS SQL Server > Upscene Productionshttp://www.upscene.com > My thoughts:http://blog.upscene.com/martijn/ > Database development questions? Check the forum!http://www.databasedevelopmentforum.com As a force of habit, I tend to do limit x (usually 1) if I'm executing an update or a delete simply for the fact that I might accidentally create a sql statement that modifies more items than I wanted to by accident. Just a thought.