Query build time problem when update views from 3.7 to 3.8 / Taxonomy exposed filter

With the update from 3.7 to 3.8 i have this problem:

https://drupal.org/node/2276389

Only solution: Back to the version 3.7!

With the version 3.8, the query build time has every time about 5 seconds. But with the version 3.7, all is well.