Using <literal>ONLY</literal> to add or drop a constraint on only

the partitioned table is supported as long as there are no

partitions. Once partitions exist, using <literal>ONLY</literal>

will result in an error. Instead, constraints on the partitions

will result in an error for any constraints other than

<literal>UNIQUE</literal> and <literal>PRIMARY KEY</literal>.

Instead, constraints on the partitions

themselves can be added and (if they are not present in the parent

table) dropped.

</para>