On Wed, Feb 4, 2009 at 10:54 AM, Jônatas Zechim <zechim.php@xxxxxxxxx>wrote: > For example i've this query: > > > > *SELECT admin_nome FROM ctalk_admin WHERE admin_lastping <= '1233762658' > AND admin_lastping >= '1233762608' AND admin_id='1'* > > > > I ran explain, the result for extra is 'Impossible WHERE noticed after > reading const table...' > > How can i optimize this query? > > Is there some tutorial on the net? > > > > Thanks, > > Zechim > > > > *De:* Bastien Koert [mailto:phpster@xxxxxxxxx] > *Enviada em:* quarta-feira, 4 de fevereiro de 2009 12:46 > *Para:* Jônatas Zechim > *Cc:* php-general@xxxxxxxxxxxxx > *Assunto:* Re: Mutiple SQL request > > > > > > On Wed, Feb 4, 2009 at 9:43 AM, Jônatas Zechim <zechim.php@xxxxxxxxx> > wrote: > > Hi there, i've a system that do a query each 3s, does it impact on mysql > Server? > I mean, can this slow my Server? > > zechim > > > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > > > It impacts system recources if this same query is run constantly for each > user. Example: if this runs a logon and you have 100 or 1000 users logging > on at roughly the same time, then you will have contention for the > resources. > > Can you check your indeces and run explain plans on the queries to see if > any of them can be optimised to run quicker? > > -- > > Bastien > > Cat, the other other white meat > Can you dump the table structure to show us how you've set it up? -- Bastien Cat, the other other white meat
