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. 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. Is the reason for 'C' in upper-case to avoid possible conflict with 'c' of log_line_prefix? 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. Otherwise all looks fine to me except the lack of documentation. regards. -- Kyotaro Horiguchi NTT Open Source Software Center
