Hi, When we try to create partitioning table based on a column , If that table contains a primary key or unique key ,it gives error saying "UNIQUE constraint on table "ac" lacks column "abc" which is part of the partition key".
this is not supported yet.
See: https://www.postgresql.org/docs/12/ddl-partitioning.html that says
"Unique constraints on partitioned tables must include all the partition key
This limitation exists because PostgreSQL can only enforce uniqueness in
each partition individually."
It is because PostgreSQL doesn't have any "global index" support yet. If you
really want to partition you table on a key that is not in the partition
key, you may have a look at