On 2022/01/27 17:10, Kyotaro Horiguchi wrote:
At Tue, 25 Jan 2022 16:02:39 +0900, Fujii Masao <masao.fu...@oss.nttdata.com>
wrote in
Hi,
Commit 6e0cb3dec1 allowed postgres_fdw.application_name to include
escape sequences %a (application name), %d (database name), %u (user
name) and %p (pid). In addition to them, I'd like to support the
escape sequence (e.g., %C) for cluster name there. This escape
sequence is helpful to investigate where each remote transactions came
from. Thought?
Patch attached.
I don't object to adding more meaningful replacements, but more escape
sequence makes me anxious about the increased easiness of exceeding
the size limit of application_name.
If this is really an issue, it might be time to reconsider the size limit of
application_name. If it's considered too short, the patch that enlarges it
should be proposed separately.
Considering that it is used to
identify fdw-initinator server, we might need to add padding (or
rather truncating) option in the escape sequence syntax, then warn
about truncated application_names for safety.
I failed to understand this. Could you tell me why we might need to add padding
option here?
Is the reason for 'C' in upper-case to avoid possible conflict with
'c' of log_line_prefix?
Yes.
I'm not sure that preventive measure is worth
doing. Looking the escape-sequence spec alone, it seems to me rather
strange that an upper-case letter is used in spite of its lower-case
is not used yet.
I have no strong opinion about using %C. If there is better character for the
escape sequence, I'm happy to use it. So what character is more proper? %c?
Otherwise all looks fine to me except the lack of documentation.
The patch updated postgres-fdw.sgml, but you imply there are other documents
that the patch should update? Could you tell me where the patch should update?
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION
