Guidelines for Row Partitioning - Teradata Vantage

The key guideline for determining the optimum granularity for the row partitions of a partitioned table is the nature of the workloads that most commonly access the PPI table or join index. The higher the number of row partitions you define for a partitioned table, the more likely an appropriate range query against the table performs more quickly, given that the partition granularity is such that the Optimizer can eliminate all but one partition.

However, avoid specifying too fine a partition granularity. For example if query workloads never access data at a granularity of less than one month, there is no benefit to be gained by defining partitions with a granularity of less than one month. Furthermore, unnecessarily fine partition granularity is likely to increase the maintenance load for a partitioned table, which can lead to overall system performance degradation. So even though too fine a partition granularity itself does not introduce performance degradations, the underlying maintenance on such a table can indirectly degrade performance.