# pg_partition_columns

The `pg_partition_columns` system view is used to show the partition key columns of a partitioned table.



Table 1. `pg_catalog.pg_partition_columns`

| column                      | type     | references | description                                                  |
| :-------------------------- | :------- | :--------- | :----------------------------------------------------------- |
| `schemaname`                | name     |            | The name of the schema the partitioned table is in.          |
| `tablename`                 | name     |            | The table name of the top-level parent table.                |
| `columnname`                | name     |            | The name of the partition key column.                        |
| `partitionlevel`            | smallint |            | The level of this subpartition in the hierarchy.             |
| `position_in_partition_key` | integer  |            | For list partitions you can have a composite (multi-column) partition key. This shows the position of the column in a composite key. |