I did not notice until today that there is some ambiguity in this paragraph:
bgw_restart_time is the interval, in seconds, that postgres should wait before restarting the process, in case it crashes. It can be any positive value, or BGW_NEVER_RESTART, indicating not to restart the process in case of a crash. I had been reading "in case _it_ crashes" and "in case of _a_ crash" as "in case _the background worker_ crashes", so I assumed with BGW_NEVER_RESTART I was saying I don't want my worker restarted if _it_ flakes out while PG is otherwise operating normally. But I was surprised when the unrelated crash of a different, normal backend left my background worker killed and never restarted. I had always regarded the fatal-error kick-out-all-backends-and-recover handling as essentially equivalent to a PG restart, so I had expected it to start the bgworker over just as a real restart would. But sure enough, ResetBackgroundWorkerCrashTimes() gets called in that case, and treats every worker with BGW_NEVER_RESTART as gone and forgotten. So it seems the "it" in "it crashes" can be "the background worker" or "postgres itself" or "any shmem-connected backend". If the wording fooled me it might fool somebody else too. I can work on wordsmithing a patch to match the doc to the behavior, but wanted first to check that the behavior is what was intended. -Chap
