某ヘ社なら雑に診断してもらえるよ
$ heroku pg:diagnose
RED: Hit Rate
Name Ratio
overall cache hit rate 0.5014303414998416
YELLOW: Indexes
Reason Index Index_scan_pct Scans_per_write Index_size Table_size
Low Scans, High Writes public.statuses::index_statuses_20190820 1.35 0.17 341 MB 2114 MB
Low Scans, High Writes public.statuses::index_statuses_on_in_reply_to_id 3.30 0.41 180 MB 2114 MB
Low Scans, High Writes public.statuses::index_statuses_on_in_reply_to_account_id 0.01 0.00 159 MB 2114 MB
GREEN: Connection Count
GREEN: Long Queries
GREEN: Long Transactions
GREEN: Idle in Transaction
GREEN: Bloat
GREEN: Blocking Queries
GREEN: Sequences
GREEN: Table Transaction ID Wraparound
GREEN: Database Transaction ID Wraparound
GREEN: Schema Count
GREEN: Load
キャッシュにかかってないのはたぶん新しいトゥートがどんどん来てるのでしょーがない。