Charts timeout on the first load

[smacker]

For me it took 3 refreshes and 15 minutes to get data for all charts.
Superset doesn't respond at all during generating data for the charts. (all pages just "loading" until requests to gitbase finish with success of timeout)

[se7entyse7en]

This issue it's very old, let's see if with latest version still has the same problem. It was the case with gsc, I actually didn't remember to have struggled that much with gitbase + default charts. Let's close this if it doesn't apply anymore or let's discuss about how we could improve this.

[se7entyse7en]

Okay I've just read that this should be fixed by closing #307.

[smacker]

yes. It's better now than at the time when the issue was opened but on a big dataset it would still timeout.