pg_partition

The pg_partition system catalog table is used to track partitioned tables and their inheritance level relationships. Each row of pg_partition represents either the level of a partitioned table in the partition hierarchy, or a subpartition template description. The value of the attribute paristemplate determines what a particular row represents.

Table 1. pg_catalog.pg_partition

column	type	references	description
parrelid	oid	pg_class_internal.oid	The object identifier of the table.
parkind	char		The partition type - R for range or L for list.
parlevel	smallint		The partition level of this row: 0 for the top-level parent table, 1 for the first level under the parent table, 2 for the second level, and so on.
paristemplate	boolean		Whether or not this row represents a subpartition template definition (true) or an actual partitioning level (false).
parnatts	smallint		The number of attributes that define this level.
paratts	int2vector		An array of the attribute numbers (as in pg_attribute.attnum) of the attributes that participate in defining this level.
parclass	oidvector	pg_opclass.oid	The operator class identifier(s) of the partition columns.