**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

const StorageInMemoryMetadata & new_metadata, const StorageInMemoryMetadata & old_metadata, bool attach) const
{
    if (!new_metadata.sorting_key.definition_ast)
        throw Exception("ORDER BY cannot be empty", ErrorCodes::BAD_ARGUMENTS);
    KeyDescription new_sorting_key = new_metadata.sorting_key;
    KeyDescription new_primary_key = new_metadata.primary_key;
    size_t sorting_key_size = new_sorting_key.column_names.size();
    size_t primary_key_size = new_primary_key.column_names.size();
    if (primary_key_size > sorting_key_size)
        throw Exception("Primary key must be a prefix of the sorting key, but its length: "
            + toString(primary_key_size) + " is greater than the sorting key length: " + toString(sorting_key_size),
            ErrorCodes::BAD_ARGUMENTS);
    NameSet primary_key_columns_set;
    for (size_t i = 0; i < sorting_key_size; ++i)
    {
        const String & sorting_key_column = new_sorting_key.column_names[i];
        if (i < primary_key_size)
        {
            const String & pk_column = new_primary_key.column_names[i];
            if (pk_column != sorting_key_column)
                throw Exception("Primary key must be a prefix of the sorting key, but in position "
                    + toString(i) + " its column is " + pk_column + ", not " + sorting_key_column,
                    ErrorCodes::BAD_ARGUMENTS);
            if (!primary_key_columns_set.emplace(pk_column).second)
                throw Exception("Primary key contains duplicate columns", ErrorCodes::BAD_ARGUMENTS);