**Describe the bug**

I have a table like:

```
CREATE TABLE test (
    time DateTime64(3)
    ...
) ENGINE = MergeTree()
PARTITION BY toStartOfInterval(time, INTERVAL 1 HOUR)
...
```

But when I search in `system.parts` it does not appear to have the `min/max` columns appropriately set?

```
partition:                             2020-06-01 01:00:00
min_date:                              1970-01-01
max_date:                              1970-01-01
min_time:                              1970-01-01 00:00:00
max_time:                              1970-01-01 00:00:00
```

I assume that if these were correctly set, doing a `select toStartOfInterval(time, interval 1 day), count()` type query would be pretty instant rather than trying to scan everything? I am guessing this is due to the `DateTime64` type in use?

Clickhouse 20.11.3.3

{
    std::lock_guard lock(query_id_set_mutex);
    if (query_id_set.find(query_id) == query_id_set.end())
        LOG_WARNING(log, "We have query_id removed but it's not recorded. This is a bug");
    else
        query_id_set.erase(query_id);
}
ReservationPtr MergeTreeData::balancedReservation(
    const StorageMetadataPtr & metadata_snapshot,
    size_t part_size,
    size_t max_volume_index,
    const String & part_name,
    const MergeTreePartInfo & part_info,
    MergeTreeData::DataPartsVector covered_parts,
    std::optional<CurrentlySubmergingEmergingTagger> * tagger_ptr,
    const IMergeTreeDataPart::TTLInfos * ttl_infos,
    bool is_insert)
{
    ReservationPtr reserved_space;
    auto min_bytes_to_rebalance_partition_over_jbod = getSettings()->min_bytes_to_rebalance_partition_over_jbod;
    if (tagger_ptr && min_bytes_to_rebalance_partition_over_jbod > 0 && part_size >= min_bytes_to_rebalance_partition_over_jbod)
    try
    {
        const auto & disks = getStoragePolicy()->getVolume(max_volume_index)->getDisks();
        std::map<String, size_t> disk_occupation;