Explanation:
Box 1: HASH
DISTRIBUTION = HASH ( distribution_column_name ) Assigns each row to one distribution by hashing the value stored in distribution_column_name. The algorithm is deterministic, which means it always hashes the same value to the same distribution. The distribution column should be defined as NOT NULL because all rows that have NULL are assigned to the same distribution.
Box 2: OrderDateKey
In most cases, table partitions are created on a date column.
A way to eliminate rollbacks is to use Metadata Only operations like partition switching for data management. For example, rather than execute a DELETE statement to delete all rows in a table where the order_date was in October of 2001, you could partition your data early. Then you can switch out the partition with data for an empty partition from another table.
Reference:
https://docs.microsoft.com/en-us/sql/t-sql/statements/create-table-azure-sql-data-warehouse
https://docs.microsoft.com/en-us/azure/synapse-analytics/sql/best-practices-dedicated-sql-pool