On 10/25/21, 10:02 AM, "Robert Haas" <robertmh...@gmail.com> wrote: > I don't see why this patch should need to make any changes to > internal_load_library(), PostmasterMain(), SubPostmasterMain(), or any > other central point of control, and I don't think it should. > pgarch_archiveXlog() can just load the library at the time it's > needed. That way it only gets loaded in the archiver process, and the > required changes are much more localized. Like instead of asserting > that the functions are initialized, just > load_external_function(libname, "_PG_archive_module_init") and call it > if they aren't.
IIUC this would mean that archive modules that need to define GUCs or register background workers would have to separately define a _PG_init() and be loaded via shared_preload_libraries in addition to archive_library. That doesn't seem too terrible to me, but it was something I was trying to avoid. > I think the attempt in check_archive_command()/check_archive_library() > to force exactly one of those two to be set is not going to work well > and should be removed. In general, GUCs whose legal values depend on > the values of other GUCs don't end up working out well. I think what > should happen instead is that if archive_library=shell then > archive_command does whatever it does; otherwise archive_command is > without effect. I'm fine with this approach. I'll go this route in the next revision. Nathan
