"Raymond O'Donnell" <rod@iol.ie> writes:
> If I want to get dates in the European format, what's the difference
> between (a) including -o -e on the postmaster command line and (b)
> uncommenting datestyle='iso,dmy' in postgresql.conf?
> If there's no difference, which is the preferred/recommended method?
Command-line switches are mostly useful for quick-and-dirty manual
starts of the postmaster; which is something people do for testing
purposes, but certainly not in production environments. In a production
environment you should almost always edit postgresql.conf, for these
reasons:
1. The postgresql.conf file allows better documentation of what
you did.
2. To insert a command-line switch, you probably have to modify the
postmaster-launching script, which means you risk losing the change
during software updates.
3. Command-line switches override postgresql.conf entries, which means
it'll be impossible to change your mind later by editing postgresql.conf
and SIGHUP'ing; only a postmaster shutdown and restart can fix it if
you change your mind about something specified on the command line.
(Of course, this doesn't carry any weight for stuff that requires a
restart to change anyway, such as shared_buffers; but for stuff that
can be changed without a restart, such as the default datestyle,
I think it's foolish to foreclose the option.)
regards, tom lane