Add error about the use of FREEZE in COPY TO

Also clarify some other error wording.

Reported-by: Kyotaro Horiguchi

Discussion: https://postgr.es/m/20220802.133046.1941977979333284049.horikyota.ntt@gmail.com

Backpatch-through: master

doc/src/sgml/ref/copy.sgml

@@ -224,6 +224,7 @@ COPY { <replaceable class="parameter">table_name</replaceable> [ ( <replaceable
       open and there are no older snapshots held by this transaction.  It is
       currently not possible to perform a <command>COPY FREEZE</command> on
       a partitioned table.
+      This option is only allowed in <command>COPY FROM</command>.
      </para>
      <para>
       Note that all other sessions will immediately be able to see the data

src/backend/commands/copy.c

@@ -671,7 +671,7 @@ ProcessCopyOptions(ParseState *pstate,
 	if (!opts_out->csv_mode && opts_out->quote != NULL)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("COPY quote available only in CSV mode")));
+				 errmsg("COPY QUOTE requires CSV mode")));
 
 	if (opts_out->csv_mode && strlen(opts_out->quote) != 1)
 		ereport(ERROR,
@@ -687,7 +687,7 @@ ProcessCopyOptions(ParseState *pstate,
 	if (!opts_out->csv_mode && opts_out->escape != NULL)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("COPY escape available only in CSV mode")));
+				 errmsg("COPY ESCAPE requires CSV mode")));
 
 	if (opts_out->csv_mode && strlen(opts_out->escape) != 1)
 		ereport(ERROR,
@@ -698,46 +698,52 @@ ProcessCopyOptions(ParseState *pstate,
 	if (!opts_out->csv_mode && (opts_out->force_quote || opts_out->force_quote_all))
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("COPY force quote available only in CSV mode")));
+				 errmsg("COPY FORCE_QUOTE requires CSV mode")));
 	if ((opts_out->force_quote || opts_out->force_quote_all) && is_from)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("COPY force quote only available using COPY TO")));
+				 errmsg("COPY FORCE_QUOTE cannot be used with COPY FROM")));
 
 	/* Check force_notnull */
 	if (!opts_out->csv_mode && opts_out->force_notnull != NIL)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("COPY force not null available only in CSV mode")));
+				 errmsg("COPY FORCE_NOT_NULL requires CSV mode")));
 	if (opts_out->force_notnull != NIL && !is_from)
 		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("COPY force not null only available using COPY FROM")));
+				 errmsg("COPY FORCE_NOT_NULL cannot be used with COPY TO")));
 
 	/* Check force_null */
 	if (!opts_out->csv_mode && opts_out->force_null != NIL)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("COPY force null available only in CSV mode")));
+				 errmsg("COPY FORCE_NULL requires CSV mode")));
 
 	if (opts_out->force_null != NIL && !is_from)
 		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("COPY force null only available using COPY FROM")));
+				 errmsg("COPY FORCE_NULL cannot be used with COPY TO")));
 
 	/* Don't allow the delimiter to appear in the null string. */
 	if (strchr(opts_out->null_print, opts_out->delim[0]) != NULL)
 		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("COPY delimiter must not appear in the NULL specification")));
+				 errmsg("COPY delimiter character must not appear in the NULL specification")));
 
 	/* Don't allow the CSV quote char to appear in the null string. */
 	if (opts_out->csv_mode &&
 		strchr(opts_out->null_print, opts_out->quote[0]) != NULL)
 		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("CSV quote character must not appear in the NULL specification")));
 
+	/* Check freeze */
+	if (opts_out->freeze && !is_from)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("COPY FREEZE cannot be used with COPY TO")));
+
 	if (opts_out->default_print)
 	{
 		if (!is_from)

src/test/regress/expected/copy2.out

@@ -83,17 +83,17 @@ ERROR:  cannot specify DELIMITER in BINARY mode
 COPY x to stdin (format BINARY, null 'x');
 ERROR:  cannot specify NULL in BINARY mode
 COPY x to stdin (format TEXT, force_quote(a));
-ERROR:  COPY force quote available only in CSV mode
+ERROR:  COPY FORCE_QUOTE requires CSV mode
 COPY x from stdin (format CSV, force_quote(a));
-ERROR:  COPY force quote only available using COPY TO
+ERROR:  COPY FORCE_QUOTE cannot be used with COPY FROM
 COPY x to stdout (format TEXT, force_not_null(a));
-ERROR:  COPY force not null available only in CSV mode
+ERROR:  COPY FORCE_NOT_NULL requires CSV mode
 COPY x to stdin (format CSV, force_not_null(a));
-ERROR:  COPY force not null only available using COPY FROM
+ERROR:  COPY FORCE_NOT_NULL cannot be used with COPY TO
 COPY x to stdout (format TEXT, force_null(a));
-ERROR:  COPY force null available only in CSV mode
+ERROR:  COPY FORCE_NULL requires CSV mode
 COPY x to stdin (format CSV, force_null(a));
-ERROR:  COPY force null only available using COPY FROM
+ERROR:  COPY FORCE_NULL cannot be used with COPY TO
 -- too many columns in column list: should fail
 COPY x (a, b, c, d, e, d, c) from stdin;
 ERROR:  column "d" specified more than once