INHERIT;
</programlisting>
   (The check constraint will not be inherited by future children, either.)
  </para>

  <para>
   To remove a check constraint from a table and all its children:
<programlisting>
ALTER TABLE distributors DROP CONSTRAINT zipchk;
</programlisting>
  </para>

  <para>
   To remove a check constraint from one table only:
<programlisting>
ALTER TABLE ONLY distributors DROP CONSTRAINT zipchk;
</programlisting>
   (The check constraint remains in place for any child tables.)
  </para>

  <para>
   To add a foreign key constraint to a table:
<programlisting>
ALTER TABLE distributors ADD CONSTRAINT distfk FOREIGN KEY (address) REFERENCES addresses (address);
</programlisting>
  </para>

  <para>
   To add a foreign key constraint to a table with the least impact on other work:
<programlisting>
ALTER TABLE distributors ADD CONSTRAINT distfk FOREIGN KEY (address) REFERENCES addresses (address) NOT VALID;
ALTER TABLE distributors VALIDATE CONSTRAINT distfk;
</programlisting>
  </para>

  <para>
   To add a (multicolumn) unique constraint to a table:
<programlisting>
ALTER TABLE distributors ADD CONSTRAINT dist_id_zipcode_key UNIQUE (dist_id, zipcode);
</programlisting>
  </para>

  <para>
   To add an automatically named primary key constraint to a table, noting
   that a table can only ever have one primary key:
<programlisting>
ALTER TABLE distributors ADD PRIMARY KEY (dist_id);
</programlisting>
  </para>

  <para>
   To move a table to a different tablespace:
<programlisting>
ALTER TABLE distributors SET TABLESPACE fasttablespace;
</programlisting>
  </para>

  <para>
   To move a table to a different schema:
<programlisting>
ALTER TABLE myschema.distributors SET SCHEMA yourschema;
</programlisting>
  </para>

  <para>
   To recreate a primary key constraint, without blocking updates while the
   index is rebuilt:
<programlisting>
CREATE UNIQUE INDEX CONCURRENTLY dist_id_temp_idx ON distributors (dist_id);
ALTER TABLE distributors DROP CONSTRAINT distributors_pkey,
    ADD CONSTRAINT distributors_pkey PRIMARY KEY USING INDEX dist_id_temp_idx;
</programlisting></para>

  <para>
   To attach a partition to a range-partitioned table:
<programlisting>
ALTER TABLE measurement
    ATTACH PARTITION measurement_y2016m07