**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

{
    auto policy = getStoragePolicy();
    if (move_ttl.destination_type == DataDestinationType::VOLUME)
    {
        auto volume = policy->getVolumeByName(move_ttl.destination_name);
        if (!volume)
            return {};
        if (is_insert && !volume->perform_ttl_move_on_insert)
            return {};
        return volume;
    }
    else if (move_ttl.destination_type == DataDestinationType::DISK)
    {
        auto disk = policy->getDiskByName(move_ttl.destination_name);
        if (!disk)
            return {};
        auto volume = policy->getVolume(policy->getVolumeIndexByDisk(disk));
        if (!volume)
            return {};
        if (is_insert && !volume->perform_ttl_move_on_insert)
            return {};
        return disk;
    }
    else
        return {};
}
bool MergeTreeData::isPartInTTLDestination(const TTLDescription & ttl, const IMergeTreeDataPart & part) const