Window partitioning

You can divide a table or rowset into partitions that are based on the values of specific columns. For example, you can partition sales data by the store ID. If you do not specify partitioning, the system considers the entire table or rowset to be a single partition.

<window partition clause> ::= partition by <column reference list>
<column reference list> ::= <value_expression>

The resulting window is partitioned into one or as many partitions as there are rows in the input virtual table, based on the values of one or more columns that are referenced in the <window partition clause>.

Each partition has one or more rows, and the values of the partition columns are equal among all rows of the partition.