Yes, the primary key in the hierarchical database is a composite key of the full lineage. The motivation for that is enforcing uniqueness. When the primary key

Yes, the primary key in the hierarchical database is a composite key of the full lineage. The motivation for that is enforcing uniqueness. When the primary key (PK) contains the sharding key, the database can easily push down the PK constraint to the related shard and enforce the PK's uniqueness.