Doc: Improve clarity on partitioned table limitations

Explicitly mention that primary key constraints are also included in the
limitation that the constraint columns must be a superset of the partition key
columns.

Wording suggestion from Tom Lane.

Discussion: https://postgr.es/m/64062533.78364.1601415362244@mail.yahoo.com
Backpatch-through: 11, where unique constraints on partitioned tables were added
This commit is contained in:
David Rowley 2020-09-30 13:02:08 +13:00
parent a094c8ff53
commit 2b888647d8

View File

@ -4056,8 +4056,8 @@ ALTER INDEX measurement_city_id_logdate_key
<listitem>
<para>
Unique constraints on partitioned tables must include all the
partition key columns. This limitation exists because
Unique constraints (and hence primary keys) on partitioned tables must
include all the partition key columns. This limitation exists because
<productname>PostgreSQL</productname> can only enforce
uniqueness in each partition individually.
</para>