**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.
{
    shutdown();
}
void StorageMergeTree::read(
    QueryPlan & query_plan,
    const Names & column_names,
    const StorageMetadataPtr & metadata_snapshot,
    SelectQueryInfo & query_info,
    ContextPtr local_context,
    QueryProcessingStage::Enum processed_stage,
    size_t max_block_size,
    unsigned num_streams)
{
    
    bool enable_parallel_reading = local_context->getClientInfo().collaborate_with_initiator;
    if (enable_parallel_reading)
        LOG_TRACE(log, "Parallel reading from replicas enabled {}", enable_parallel_reading);
    if (auto plan = reader.read(
        column_names, metadata_snapshot, query_info, local_context, max_block_size, num_streams, processed_stage, nullptr, enable_parallel_reading))
        query_plan = std::move(*plan);
}
Pipe StorageMergeTree::read(