Conpherenece - improve performance by not fetching data as often from D12347

Summary: Turns out the pertinent views don't use this data anyway. Additonally, change the remaining pathway to fetch 15% of the rows it fetched in D12347. Fixes T7815.

Test Plan: clicked around and things worked. my instance always feels snappy though

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7815

Differential Revision: https://secure.phabricator.com/D12399