Data partitioning is defined as a table property, and is implemented on all projections of that table. On all load, refresh, and recovery operations, the Vertica Tuple Mover automatically partitions data into separate ROS containers. Each ROS container contains data for a single partition or partition group; depending on space requirements, a partition or partition group can span multiple ROS containers.
For example, it is common to partition data by time slices. If a table contains decades of data, you can partition it by year. If the table contains only one year of data, you can partition it by month.
Logical divisions of data can significantly improve query execution. For example, if you query a table on a column that is in the table's partition clause, the query optimizer can quickly isolate the relevant ROS containers (see Partition Pruning).
Partitions can also facilitate DML operations. For example, given a table that is partitioned by months, you might drop all data for the oldest month when a new month begins. In this case, Vertica can easily identify the ROS containers that store the partition data to drop. For details, see Managing Partitions.