Обсуждение: What does log_destination = csvlog mean?
In reading through our documentation, I am unclear how "log_destination = csvlog" works. It seems to me that 'cvslog' is a format-output type, not a real destination, or rather it is a special output format for stderr. Is this accurate? I would like to clarify our documentation. -- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. +
Bruce Momjian wrote: > In reading through our documentation, I am unclear how "log_destination > = csvlog" works. It seems to me that 'cvslog' is a format-output type, > not a real destination, or rather it is a special output format for > stderr. Is this accurate? I would like to clarify our documentation. > > CSV logs can in fact only be delivered via redirected stderr, i.e. csvlog requires that logging_collector be on. So in a sense it's both a format and a destination. There is a strong technical reason for that, namely that only by doing that can be be sure that CSV logs won't get lines multiplexed, which would make loading them back into a table impossible. We invented a whole (simple) protocol between the backends and the syslogger just to handle that. cheers andrew
Andrew Dunstan wrote: > > > Bruce Momjian wrote: > > In reading through our documentation, I am unclear how "log_destination > > = csvlog" works. It seems to me that 'cvslog' is a format-output type, > > not a real destination, or rather it is a special output format for > > stderr. Is this accurate? I would like to clarify our documentation. > > > > > > CSV logs can in fact only be delivered via redirected stderr, i.e. > csvlog requires that logging_collector be on. So in a sense it's both a > format and a destination. > > There is a strong technical reason for that, namely that only by doing > that can be be sure that CSV logs won't get lines multiplexed, which > would make loading them back into a table impossible. We invented a > whole (simple) protocol between the backends and the syslogger just to > handle that. That's what I thought; thanks. -- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. +