tpch1000s=# select c.relname, policytype, numsegments, distkey 
from pg_class c, pg_catalog.gp_distribution_policy gpp 
where c.oid = gpp.localoid;
 relname  | policytype | numsegments | distkey 
----------+------------+-------------+---------
 nation   | p          |         192 | 1
 region   | p          |         192 | 1
 part     | p          |         192 | 1