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
