Looks like https://github.com/ClickHouse/ClickHouse/pull/21303 is broke also "clear column" for such columns.

How to reproduce:

```
CREATE TABLE test.TTAdmLog
(
    `ts` DateTime,
    `event_date` Date DEFAULT toDate(ts),
    `impression_id` String DEFAULT '',
    `creative_id` String DEFAULT '',
    `creative_adm` String DEFAULT '',
    `impression_id_compressed` FixedString(16) DEFAULT UUIDStringToNum(impression_id),
    `impression_id_hashed` UInt16 DEFAULT reinterpretAsUInt16(impression_id_compressed),
)
ENGINE = ReplicatedMergeTree('/clickhouse/tables/{shard}/TTAdmLogTest', '{replica}')
PARTITION BY toMonday(event_date)
ORDER BY (event_date, impression_id_hashed)
SAMPLE BY impression_id_hashed
SETTINGS replicated_deduplication_window = 1000, replicated_deduplication_window_seconds = 864000, index_granularity = 8192

CREATE MATERIALIZED VIEW test.TTView
(
    `event_date` Date,
    `creative_id` String,
    `creative_adm` AggregateFunction(anyLast, String),
)
ENGINE = ReplicatedAggregatingMergeTree('/clickhouse/tables/{shard}/TTViewTest', '{replica}', event_date, (event_date, creative_id), 8192) AS
SELECT 
    toStartOfMonth(event_date) AS event_date,
    arrayJoin(splitByChar(',', creative_id)) AS creative_id,
    anyLastState(creative_adm) AS creative_adm,
FROM test.TTAdmLog
GROUP BY 
    event_date,
    creative_id,

```


ClickHouse server version 20.9.3 revision 54439.

```
alter table test.TTAdmLog clear column creative_adm in partition '2021-03-22'

OK

```
ClickHouse server version 21.4.3 revision 54447.

```
alter table test.TTAdmLog  clear column creative_adm in partition '2021-03-22'

DB::Exception: Trying to ALTER DROP column creative_adm which is referenced by materialized view ['TTView'].

```

ErrorCodes::TOO_MANY_PARTS,
            "Too many parts ({}). Merges are processing significantly slower than inserts",
            parts_count_in_partition);
    }
    if (k_inactive < 0 && parts_count_in_partition < settings->parts_to_delay_insert)
        return;
    const ssize_t k_active = ssize_t(parts_count_in_partition) - ssize_t(settings->parts_to_delay_insert);
    size_t max_k;
    size_t k;
    if (k_active > k_inactive)
    {
        max_k = settings->parts_to_throw_insert - settings->parts_to_delay_insert;
        k = k_active + 1;
    }
    else
    {
        max_k = settings->inactive_parts_to_throw_insert - settings->inactive_parts_to_delay_insert;
        k = k_inactive + 1;
    }
    const double delay_milliseconds = ::pow(settings->max_delay_to_insert * 1000, static_cast<double>(k) / max_k);
    ProfileEvents::increment(ProfileEvents::DelayedInserts);
    ProfileEvents::increment(ProfileEvents::DelayedInsertsMilliseconds, delay_milliseconds);
    CurrentMetrics::Increment metric_increment(CurrentMetrics::DelayedInserts);
    LOG_INFO(log, "Delaying inserting block by {} ms. because there are {} parts", delay_milliseconds, parts_count_in_partition);
    if (until)
        until->tryWait(delay_milliseconds);
    else
        std::this_thread::sleep_for(std::chrono::milliseconds(static_cast<size_t>(delay_milliseconds)));
}
MergeTreeData::DataPartPtr MergeTreeData::getActiveContainingPart(