CB

If a user has more than 1 usergroup they will display more than once in a userlist. This is due to the inner join of the usergroup mapping table. Adding DISTINCT back causes a performance decrease at the magnitude of 600x. Causing significant performance loss. Example as follows.

Current: 0.0311 seconds
GROUP BY: 20.4404 seconds
DISTINCT: 154.7703 seconds

https://www.joomlapolis.com/forum/153-professional-member-support/240857-list-entries-showing-multiple-times-after-recent-update#311833