Retrieving job list is slow

[sylvlecl]

Description

Retrieving the list of jobs in production application takes 3 seconds.
This requires some analysis to understand what takes so long:

• retrieving from the database?
• filtering results bases on user rights etc ?

I suspect that what takes long is the check on permissions, which requires to retrieve user and group information for each involved study separately, hence a lot of requests to the database.

Expected Behavior

Such an operation should be fast (hundreds of ms maximum).

Possible Solution

If the problem comes indeed from the check on permission, we should retrieve all necessary information in only one request to database. Similar issue as #1435

Environment

• Production
• Staging