**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

ErrorCodes::ALTER_OF_COLUMN_IS_FORBIDDEN);
            }
            else if (command.type == AlterCommand::RENAME_COLUMN)
            {
                throw Exception(
                    "Trying to ALTER RENAME version " + backQuoteIfNeed(command.column_name) + " column",
                    ErrorCodes::ALTER_OF_COLUMN_IS_FORBIDDEN);
            }
        }
        if (command.type == AlterCommand::MODIFY_ORDER_BY && !is_custom_partitioned)
        {
            throw Exception(
                "ALTER MODIFY ORDER BY is not supported for default-partitioned tables created with the old syntax",
                ErrorCodes::BAD_ARGUMENTS);
        }
        if (command.type == AlterCommand::MODIFY_TTL && !is_custom_partitioned)
        {
            throw Exception(
                "ALTER MODIFY TTL is not supported for default-partitioned tables created with the old syntax",
                ErrorCodes::BAD_ARGUMENTS);
        }
        if (command.type == AlterCommand::MODIFY_SAMPLE_BY)
        {
            if (!is_custom_partitioned)
                throw Exception(
                    "ALTER MODIFY SAMPLE BY is not supported for default-partitioned tables created with the old syntax",
                    ErrorCodes::BAD_ARGUMENTS);
            checkSampleExpression(new_metadata, getSettings()->compatibility_allow_sampling_expression_not_in_primary_key);
        }
        if (command.type == AlterCommand::ADD_INDEX && !is_custom_partitioned)