Check if we need an index on experiment_structure for 4.2.0 #2645
Description
From @tiggi raised during the coding sprint in BCN: A test experiment copied from an operational has about 43K jobs (feel free to correct me if there's anything wrong) and it has grown quite a bit in the DB. Doing full table scans on that table (in 4.2.0 with the job list PR of Dani #2619) might affect the performance of server & experiments.