Api::V1::Timelines::PublicController#showも見ておこう
/app/controllers/application_controller.rb in cache_collection at line 89
/app/controllers/api/v1/timelines/public_controller.rb in cached_public_statuses at line 20
/app/controllers/api/v1/timelines/public_controller.rb in load_statuses at line 16
/app/controllers/api/v1/timelines/public_controller.rb in show at line 9
で、
SELECT "statuses"."id", "statuses"."updated_at" FROM "statuses" LEFT OUTER JOIN "accounts" ON "accounts"."id" = "statuses"."account_id" WHERE ("statuses"."local" = ? OR "statuses"."uri" IS NULL) AND "statuses"."visibility" = ? AND (statuses.reblog_of_id IS NULL) AND (statuses.reply = FALSE OR statuses.in_reply_to_account_id = statuses.account_id) AND "accounts"."silenced" = ? ORDER BY "statuses"."id" DESC LIMIT ?
が10,816.7 msかけて40行返してる例があった。