[pgpool-hackers: 4504] Proposal to backport notice_per_node_statement

[Tatsuo Ishii]

The feature is pretty useful for testing because it allows to take
psql output logs for queries pgpool sends to each backend node, then
compare the logs with expected output so that we can confirm pgpool
works as expected. This is similar to PostgreSQL's regression test. We
maybe able to do similar thing by:

pgpool set client_min_messages to log;

But this has disadvantages:

1) This will print internal rel cache access log which makes the
comparison with the expected file unstable because the log is added
depending on the pgpool relation cache.

2) The log usually includes process id, again which makes the
comparison unstable.

notice_per_node_statement does not have these disadvantages.

If we backport notice_per_node_statement, probably we should implement
it as "undocumented" feature because our policy is "do not backport
new feature to back branches". I think making it as an undocumented
feature is a good compromize.

Comments/suggestions are welcome.

Best reagards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp