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'].

```

{
    if (!distributed_settings.bytes_to_throw_insert &&
        !distributed_settings.bytes_to_delay_insert)
        return;
    UInt64 total_bytes = *totalBytes(getContext()->getSettingsRef());
    if (distributed_settings.bytes_to_throw_insert && total_bytes > distributed_settings.bytes_to_throw_insert)
    {
        ProfileEvents::increment(ProfileEvents::DistributedRejectedInserts);
        throw Exception(ErrorCodes::DISTRIBUTED_TOO_MANY_PENDING_BYTES,
            "Too many bytes pending for async INSERT: {} (bytes_to_throw_insert={})",
            formatReadableSizeWithBinarySuffix(total_bytes),
            formatReadableSizeWithBinarySuffix(distributed_settings.bytes_to_throw_insert));
    }
    if (distributed_settings.bytes_to_delay_insert && total_bytes > distributed_settings.bytes_to_delay_insert)
    {
        
        
        const size_t step_ms = std::min<double>(1., double(distributed_settings.max_delay_to_insert) * 1'000 * 0.05);
        UInt64 delayed_ms = 0;
        do {
            delayed_ms += step_ms;
            std::this_thread::sleep_for(std::chrono::milliseconds(step_ms));
        } while (*totalBytes(getContext()->getSettingsRef()) > distributed_settings.bytes_to_delay_insert && delayed_ms < distributed_settings.max_delay_to_insert*1000);
        ProfileEvents::increment(ProfileEvents::DistributedDelayedInserts);
        ProfileEvents::increment(ProfileEvents::DistributedDelayedInsertsMilliseconds, delayed_ms);
        UInt64 new_total_bytes = *totalBytes(getContext()->getSettingsRef());
        LOG_INFO(log, "Too many bytes pending for async INSERT: was {}, now {}, INSERT was delayed to {} ms",
            formatReadableSizeWithBinarySuffix(total_bytes),
            formatReadableSizeWithBinarySuffix(new_total_bytes),
            delayed_ms);