the foreign table is
     the partition chosen for tuple routing or the target specified in the
     command.
    </para>

    <para>
     If the <function>BeginForeignInsert</function> pointer is set to
     <literal>NULL</literal>, no action is taken for the initialization.
    </para>

    <para>
     Note that if the FDW does not support routable foreign-table partitions
     and/or executing <command>COPY FROM</command> on foreign tables, this
     function or <function>ExecForeignInsert/ExecForeignBatchInsert</function>
     subsequently called must throw error as needed.
    </para>

    <para>
<programlisting>
void
EndForeignInsert(EState *estate,
                 ResultRelInfo *rinfo);
</programlisting>

     End the insert operation and release resources.  It is normally not important
     to release palloc'd memory, but for example open files and connections
     to remote servers should be cleaned up.
    </para>

    <para>
     If the <function>EndForeignInsert</function> pointer is set to
     <literal>NULL</literal>, no action is taken for the termination.
    </para>

    <para>
<programlisting>
int
IsForeignRelUpdatable(Relation rel);
</programlisting>

     Report which update operations the specified foreign table supports.
     The return value should be a bit mask of rule event numbers indicating
     which operations are supported by the foreign table, using the
     <literal>CmdType</literal> enumeration; that is,
     <literal>(1 &lt;&lt; CMD_UPDATE) = 4</literal> for <command>UPDATE</command>,
     <literal>(1 &lt;&lt; CMD_INSERT) = 8</literal> for <command>INSERT</command>, and
     <literal>(1 &lt;&lt; CMD_DELETE) = 16</literal> for <command>DELETE</command>.
    </para>

    <para>
     If the <function>IsForeignRelUpdatable</function> pointer is set to
     <literal>NULL</literal>, foreign tables are assumed to be insertable, updatable,
     or deletable if the FDW provides <function>ExecForeignInsert</function>,
     <function>ExecForeignUpdate</function>, or <function>ExecForeignDelete</function>
     respectively.  This function is only needed if the FDW supports some
     tables that are updatable and some that are not.  (Even then, it's
     permissible to throw an error in the execution routine instead of
     checking in this function.  However, this function is used to determine
     updatability for display in the <literal>information_schema</literal> views.)
    </para>

    <para>
     Some inserts, updates, and deletes to foreign tables can be optimized
     by implementing an alternative set of interfaces.  The ordinary
     interfaces for inserts, updates, and deletes fetch rows from the remote
     server and then modify those rows one at a time.  In some cases, this
     row-by-row approach is necessary, but it can be inefficient.  If it is
     possible for the foreign server to determine which rows should be
     modified without actually retrieving them, and if there are no local
     structures which would affect the operation (row-level local triggers,
     stored generated columns, or <literal>WITH CHECK OPTION</literal>
     constraints from parent views), then it is possible to arrange things
     so that the entire operation is performed on the remote server.  The
     interfaces described below make this possible.
    </para>

    <para>
<programlisting>
bool
PlanDirectModify(PlannerInfo *root,
                 ModifyTable *plan,
                 Index resultRelation,
                 int subplan_index);
</programlisting>

     Decide whether it is safe to execute a direct modification
     on the remote server.  If so, return <literal>true</literal> after performing
     planning actions needed for that.  Otherwise, return <literal>false</literal>.
     This optional function is called during query planning.
     If this function succeeds, <function>BeginDirectModify</function>,
     <function>IterateDirectModify</function> and <function>EndDirectModify</function> will