title: Clickhouse table TTL does not remove old records
body: <p>I have added a TTL to this <code>GraphiteMergeTree</code> table, but old records are not being removed automatically.</p>
  <pre class="lang-sql prettyprint-override"><code>CREATE TABLE default.graphite_data
  (
      `Path` String,
      `Value` Float64,
      `Time` UInt32,
      `Date` Date,
      `Timestamp` UInt32
  )
  ENGINE = GraphiteMergeTree('graphite_rollup')
  PARTITION BY toYYYYMM(Date)
  ORDER BY (Path, Time)
  TTL Date + toIntervalQuarter(2)
  SETTINGS index_granularity = 8192
  </code></pre>
  <p>I still see old data in this table:</p>
  <pre class="lang-sql prettyprint-override"><code>SELECT *
  FROM graphite_data
  LIMIT 10
  
  ┌─Path─────────────────────────────┬─Value─┬───────Time─┬───────Date─┬──Timestamp─┐
  │ carbon.agents.test.pickle.active │     0 │ 1577833200 │ 2020-01-01 │ 1577836784 │
  │ carbon.agents.test.pickle.active │     0 │ 1577836800 │ 2020-01-01 │ 1577840384 │
  │ carbon.agents.test.pickle.active │     0 │ 1577840400 │ 2020-01-01 │ 1577843984 │
  │ carbon.agents.test.pickle.active │     0 │ 1577844000 │ 2020-01-01 │ 1577847584 │
  │ carbon.agents.test.pickle.active │     0 │ 1577847600 │ 2020-01-01 │ 1577851184 │
  │ carbon.agents.test.pickle.active │     0 │ 1577851200 │ 2020-01-01 │ 1577854784 │
  │ carbon.agents.test.pickle.active │     0 │ 1577854800 │ 2020-01-01 │ 1577858384 │
  │ carbon.agents.test.pickle.active │     0 │ 1577858400 │ 2020-01-01 │ 1577861984 │
  │ carbon.agents.test.pickle.active │     0 │ 1577862000 │ 2020-01-01 │ 1577865584 │
  │ carbon.agents.test.pickle.active │     0 │ 1577865600 │ 2020-01-01 │ 1577869184 │
  └──────────────────────────────────┴───────┴────────────┴────────────┴────────────┘
  
  10 rows in set. Elapsed: 0.029 sec.
  </code></pre>
  <p>I also did <code>OPTIMIZE FINAL</code>, but the result is still the same. What could be wrong here?</p>