CREATE TABLE without AS doesn't have anything to parallelize.
The query writes any data or locks any database rows. If a query
contains a data-modifying operation either at the top level or within
a CTE, no parallel plans for that query will be generated. As an
- exception, the commands <literal>CREATE TABLE</literal>, <literal>SELECT
+ exception, the commands <literal>CREATE TABLE ... AS</literal>, <literal>SELECT
INTO</literal>, and <literal>CREATE MATERIALIZED VIEW</literal> which create a new
table and populate it can use a parallel plan.
</para>