require all columns, but the
     FDW could choose to optimize away returning some or all columns depending
     on the contents of the <literal>RETURNING</literal> clause.  Regardless, some
     slot must be returned to indicate success, or the query's reported row
     count will be wrong.
    </para>

    <para>
     If the <function>ExecForeignDelete</function> pointer is set to
     <literal>NULL</literal>, attempts to delete from the foreign table will fail
     with an error message.
    </para>

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

     End the table update 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>EndForeignModify</function> pointer is set to
     <literal>NULL</literal>, no action is taken during executor shutdown.
    </para>

    <para>
     Tuples inserted into a partitioned table by <command>INSERT</command> or
     <command>COPY FROM</command> are routed to partitions.  If an FDW
     supports routable foreign-table partitions, it should also provide the
     following callback functions.  These functions are also called when
     <command>COPY FROM</command> is executed on a foreign table.
    </para>

    <para>
<programlisting>
void
BeginForeignInsert(ModifyTableState *mtstate,
                   ResultRelInfo *rinfo);
</programlisting>

     Begin executing an insert operation on a foreign table.  This routine is
     called right before the first tuple is inserted into the foreign table
     in both cases when it is the partition chosen for tuple routing and the
     target specified in a <command>COPY FROM</command> command.  It should
     perform any initialization needed prior to the actual insertion.
     Subsequently, <function>ExecForeignInsert</function> or
     <function>ExecForeignBatchInsert</function> will be called for
     tuple(s) to be inserted into the foreign table.
    </para>

    <para>
     <literal>mtstate</literal> is the overall state of the
     <structname>ModifyTable</structname> plan node being executed; global data about
     the plan and execution state is available via this structure.
     <literal>rinfo</literal> is the <structname>ResultRelInfo</structname> struct describing
     the target foreign table.  (The <structfield>ri_FdwState</structfield> field of
     <structname>ResultRelInfo</structname> is available for the FDW to store any
     private state it needs for this operation.)
    </para>

    <para>
     When this is called by a <command>COPY FROM</command> command, the
     plan-related global data in <literal>mtstate</literal> is not provided
     and the <literal>planSlot</literal> parameter of
     <function>ExecForeignInsert</function> subsequently called for each
     inserted tuple is <literal>NULL</literal>, whether 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>