ERRCODE_T_R_DEADLOCK_DETECTED

The error code is used in two places:

ereport(ERROR,
(errcode(ERRCODE_T_R_DEADLOCK_DETECTED),
errmsg("canceling statement due to conflict with recovery"),
errdetail("User transaction caused buffer deadlock with recovery.")));

ereport(ERROR,
(errcode(ERRCODE_T_R_DEADLOCK_DETECTED),
errmsg("deadlock detected"),
errdetail_internal("%s", clientbuf.data),
errdetail_log("%s", logbuf.data),
errhint("See server log for query details.")));

The latter is a normal deadlock and can be obseved by stats because
pgstat_report_deadlock() is called.

The former is using the same error code but the meaning is pretty
different and users might be confused IMO.

I am not sure sharing the same error code is the best idea here.

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp