Issue ERROR if FREEZE mode can't be honored by COPY

Previously non-honored FREEZE mode was ignored.  This also issues an
appropriate error message based on the cause of the failure, per
suggestion from Tom.  Additional regression test case added.

1 files changed, 4 insertions, 8 deletions

diff --git a/doc/src/sgml/ref/copy.sgml b/doc/src/sgml/ref/copy.sgml
index 6a0fabc978d..2137c67cb4b 100644
--- a/doc/src/sgml/ref/copy.sgml
+++ b/doc/src/sgml/ref/copy.sgml
@@ -190,18 +190,14 @@ COPY { <replaceable class="parameter">table_name</replaceable> [ ( <replaceable
       would be after running the <command>VACUUM FREEZE</> command.
       This is intended as a performance option for initial data loading.
       Rows will be frozen only if the table being loaded has been created
-      in the current subtransaction, there are no cursors open and there
-      are no older snapshots held by this transaction. If those conditions
-      are not met the command will continue without error though will not
-      freeze rows. It is also possible in rare cases that the request
-      cannot be honoured for internal reasons, hence <literal>FREEZE</literal>
-      is more of a guideline than a hard rule.
+      or truncated in the current subtransaction, there are no cursors
+      open and there are no older snapshots held by this transaction.
      </para>
      <para>
       Note that all other sessions will immediately be able to see the data
       once it has been successfully loaded. This violates the normal rules
-      of MVCC visibility and by specifying this option the user acknowledges
-      explicitly that this is understood.
+      of MVCC visibility and users specifying should be aware of the
+      potential problems this might cause.
      </para>
     </listitem>
    </varlistentry>