TeamMembership:+index timeout deleting a member

https://lp-oops.canonical.com/oops.py/?oopsid=1755ED1750
https://edge.launchpad.net/%7Ecanonical-fae-team/+member/bobcheng/+index

Branch: launchpad-rev-11704
Revno: 11704
SQL time: 12684 ms
Non-sql time: 642 ms
Total time: 13326 ms
Statement Count: 274

This is simple death by SQL:

160. 7965 2ms SQL-launchpad-main-master SELECT Person.account, Person.creation_comment, Person.creation_rationale, Person.datecreated, Person.defaultmembershipperiod, Person.defaultrenewalperiod, Person.displayname, Person.hide_email_addresses, Person.homepage_content, Person.icon, Person.id, Person.logo, Person.mailing_list_auto_subscribe_policy, Person.merged, Person.mugshot, Person.name, Person.personal_standing, Person.personal_standing_reason, Person.registrant, Person.renewal_policy, Person.subscriptionpolicy, Person.teamdescription, Person.teamowner, Person.verbose_bugnotifications, Person.visibility FROM Person WHERE id IN ( -- All the super teams... SELECT team FROM TeamParticipation WHERE person = 2234420 AND team != 2234420 EXCEPT -- The one where person has an active membership. SELECT team FROM TeamMembership WHERE person = 3350139 AND status IN (3, 2) ) ORDER BY person_sort_key(Person.displayname, Person.name)
161. 7968 67ms SQL-launchpad-main-master SELECT EXISTS( SELECT 1 FROM TeamParticipation, TeamMembership WHERE TeamMembership.team = 3119008 AND TeamMembership.person = TeamParticipation.team AND TeamParticipation.person = 3350139 AND TeamMembership.status IN (3, 2))
162. 8036 1ms SQL-launchpad-main-master DELETE FROM TeamParticipation WHERE TeamParticipation.team = %s AND TeamParticipation.person = %s

repeats hundreds of times.

I'm arranging for a temporary timeout exception for this to unblock the user.
Changing this to just do a 4 queries should fix it for everything up to to thousands of teams.