Hi,
That log doesn't give any information on why the load would increase unfortunately.
We didn't notice any change on our end. In fact it's even the opposite as we greatly improved the load on the checkout when displaying payment/shipping methods.
Did you see a slowdown of each page display ? Is it only on some pages ?
Which version of Joomla do you have ? PHP ? What was your previous version of HikaShop ?
Also, it could simply be a surge in traffic caused by spam bots, crawlers etc and actually not related to the update. Did you check your access logs for that ?
One other thing you could do would be to update a copy of your website and update it to a beta of Joomla 3.2 which adds a lot of profiling data to pages when the debug mode of the joomla configuration is turned on. That will allow you to see exactly what is taking time for the processing the page.