**How to reproduce**
Clickhouse server 20.13.1.5273
```
CREATE TABLE default.test
(
`key` UInt32,
`ts` DateTime CODEC(DoubleDelta, LZ4),
`db_time` DateTime DEFAULT now() COMMENT 'spout-ignore' CODEC(DoubleDelta, LZ4)
)
ENGINE = MergeTree
PARTITION BY toStartOfTenMinutes(db_time)
ORDER BY (key, ts)
TTL db_time + toIntervalHour(3)
SETTINGS index_granularity = 8192, merge_with_ttl_timeout = 3600, min_rows_for_compact_part = 1000000, min_bytes_for_compact_part = 200000000, in_memory_parts_enable_wal = 0;


INSERT INTO test(key, ts) SELECT number % 1000, now() + intDiv(number,1000) FROM numbers(500);

SELECT * FROM test;
500 rows in set. Elapsed: 0.003 sec.

DETACH TABLE test;

ATTACH TABLE test;

SELECT * FROM test;

0 rows in set. Elapsed: 0.002 sec.
```

**Expected behavior**
Clickhouse would flush parts on disk.
{
    return getTotalActiveSizeInRows();
}
std::optional<UInt64> StorageMergeTree::totalRowsByPartitionPredicate(const SelectQueryInfo & query_info, ContextPtr local_context) const
{
    auto parts = getDataPartsVector({DataPartState::Committed});
    return totalRowsByPartitionPredicateImpl(query_info, local_context, parts);
}
std::optional<UInt64> StorageMergeTree::totalBytes(const Settings &) const
{
    return getTotalActiveSizeInBytes();
}
SinkToStoragePtr
StorageMergeTree::write(const ASTPtr & , const StorageMetadataPtr & metadata_snapshot, ContextPtr local_context)
{
    const auto & settings = local_context->getSettingsRef();
    return std::make_shared<MergeTreeSink>(
        *this, metadata_snapshot, settings.max_partitions_per_insert_block, local_context);
}
void StorageMergeTree::checkTableCanBeDropped() const