Loading an evolution graph takes a very long time. Sometimes > 1 Minute. In comparison a normal graph takes only 1 or 2 seconds.
We should profile what takes that long and optimize this. For example the queries which are performed while creating the graph.
Evolution Graph should also load in 1-3 seconds if possible. Otherwise it takes too long to display the graph in Piwik Mobile since it also takes some time to download the graph (depending on the current Internet connection on the mobile device)
A bug caused by slow Row Evolution was reported in #3363
See also #3465 to do at same time
As related to #3464, @capedfuzz would you be interested in profiling with xhprof and seeing if we could quick-fix this slowness? let's not spend more than 3 hours on this, but hopefully in this short time we can find a solution to make Static Historical Graph super fast.
This would be a big plus for PIwik Mobile, which could then start using these graphs (they are disabled until they can be made faster). Thanks!
For example this graphs URL takes 3-4 seconds to generate but ideally should take 1 second max (if possible).
Optimization Idea: DataTableManipulator loads subtables one at a time. It's possible to load them all at once however (which is done when expanded=1), then access the DataTable in DataTable_Manager. Since manipulators are run after the main request though, we'll want to make sure we're not accessing the subtables twice (otherwise memory consumption will go up).
btw is this still a problem ? Or are graphs loading OK on the mobile app now?