Re: COPY TO (FREEZE)?

Bruce Momjian <bruce@momjian.us> writes:
> My apologies, wrong patch attached, right one attached now.

I think this one is fine as-is:

     /* Only single-byte delimiter strings are supported. */
     if (strlen(opts_out->delim) != 1)
         ereport(ERROR,
-                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                  errmsg("COPY delimiter must be a single one-byte character")));
 
While we have good implementation reasons for this restriction,
there's nothing illogical about wanting the delimiter to be more
general.  It's particularly silly, from an end-user's standpoint,
that for example 'é' is an allowed delimiter in LATIN1 encoding
but not when the server is using UTF8.  So I don't see how the
distinction you presented justifies this change.

+    if (opts_out->freeze && !is_from)
+        ereport(ERROR,
+                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+                 errmsg("COPY freeze only available using COPY FROM")));

Not thrilled by the wording here.  I don't like the fact that the
keyword FREEZE isn't capitalized, and I think you omitted too many
words for intelligibility to be preserved.  Notably, all the adjacent
examples use "must" or "must not", and this decides that that can be
omitted.

I realize that you probably modeled the non-capitalization on nearby
messages like "COPY delimiter", but there's a difference IMO:
"delimiter" can be read as an English noun, but it's hard to read
"freeze" as a noun.

How about, say,

    errmsg("COPY FREEZE must not be used in COPY TO")));

or perhaps that's redundant and we could write

    errmsg("FREEZE option must not be used in COPY TO")));

            regards, tom lane