Re: Add new error_action COPY ON_ERROR "log"

On Wed, Mar 06, 2024 at 07:32:28PM +0530, Bharath Rupireddy wrote:
> Please see the attached v4 patch. If it looks good, I can pull
> LOG_VERBOSITY changes out into 0001 and with 0002 containing the
> detailed messages for discarded rows.

The approach looks sensible seen from here.

+    LOG_VERBOSITY [ <replaceable class="parameter">boolean</replaceable> ]
[...]
+    <term><literal>LOG_VERBOSITY</literal></term>
+    <listitem>
+     <para>
+      Sets the verbosity of logged messages by <command>COPY</command>
+      command. As an example, see its usage for
+      <command>COPY FROM</command> command's <literal>ON_ERROR</literal>
+      clause with <literal>ignore</literal> option.
+     </para>
+    </listitem>

Is a boolean the best interface for the end-user, though?  Maybe
something like a "mode" value would speak more than a yes/no from the
start, say a "default" mode to emit only the last LOG and a "verbose"
for the whole set in the case of ON_ERROR?  That could use an enum
from the start internally, but that's an implementation detail.

Describing what gets logged in the paragraph of ON_ERROR sounds fine,
especially if in the future more logs are added depending on other
options.  That's an assumption at this stage, of course.

I am adding Alexander Korotkov in CC, as the original committer of
9e2d8701194f, as I assume that he may want to chime in this
discussion.

Torikoshi-san or others, if you have any comments about the interface,
feel free.
--
Michael