Using the explain tells me that when i supply a LIMIT query then my indexes are ignored, which i believe is the expected behaviour as according to mysql forums this is the way mysql works "out of the box"
What i'm wondering is if i choose not to use LIMIT queries then will there be any fallout to things such as batch fetch iterator as i seem to recall that the addition of LIMIT to the mysql plugin is relatively new. Thanks Robin On 7 March 2014 18:32, Klaus Berkling <[email protected]> wrote: > > On Mar 7, 2014, at 10:20 AM, Robin Smith <[email protected]> > wrote: > > I'm not sure about fetch plans, all i know at the moment is if i remove > the LIMIT query i get millisecond performance on my query but if i include > a LIMIT clause i get a full table scan. > > > You can log the query WO generates and run that through EXPLAIN? Try it > with and without the limit. > > > > On 7 March 2014 17:15, Jesse Tayler <[email protected]> wrote: > >> did you check to make sure your database is using the index fetch plan >> you expect? >> >> I recall with MySQL sometimes indexes would fail but there would be no >> indication until I actually reviewed the fetch internals... >> >> something chuck would know off the top of his head I'm sure... >> >> >> >> >> On Mar 7, 2014, at 12:02 PM, Robin Smith <[email protected]> >> wrote: >> >> Hi All >> >> We have been experiencing some performace issues with our DB queries that >> we have narrowed down to the "limitClause" applied to sql queries. It seems >> that out of the box MySQL uses no indexes when supplied with a LIMIT clause. >> >> Taking this into consideration we were wondering if anything like batch >> fetch iterator rely on the limit clause being applied to queries or if we >> could safely remove (or add switch to) this part of _MySqlPlugin. >> >> Thanks >> >> Robin >> >> -- >> Robin Smith >> Engineering Team Leader BEng (Hons) MBCS >> >> ------------------------------ >> http://www.clicktravel.com >> >> Think: Do you really need to print this email? >> _______________________________________________ >> Do not post admin requests to the list. They will be ignored. >> Webobjects-dev mailing list ([email protected]) >> Help/Unsubscribe/Update your Subscription: >> https://lists.apple.com/mailman/options/webobjects-dev/jtayler%40oeinc.com >> >> This email sent to [email protected] >> >> >> > > > -- > Robin Smith > Engineering Team Leader BEng (Hons) MBCS > > ------------------------------ > http://www.clicktravel.com > > Think: Do you really need to print this email? > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Webobjects-dev mailing list ([email protected]) > Help/Unsubscribe/Update your Subscription: > > https://lists.apple.com/mailman/options/webobjects-dev/webobjects%40berkling.us > > This email sent to [email protected] > > > > > kib > > *"We keep moving forward, opening new doors, and doing new things, because > we're curious and curiosity keeps leading us down new paths."* > Walt Disney > > *Klaus Berkling* > www.berkling.us | @kiberkli | Buy My iPhone > app<http://itunes.apple.com/us/app/exactbart!/id425068916?mt=8> > > > > > > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Webobjects-dev mailing list ([email protected]) > Help/Unsubscribe/Update your Subscription: > > https://lists.apple.com/mailman/options/webobjects-dev/robin.smith%40clicktravel.com > > This email sent to [email protected] > -- Robin Smith Engineering Team Leader BEng (Hons) MBCS -- ------------------------------ http://www.clicktravel.com Think: Do you really need to print this email?
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