Re: Add support for logging the current role

* Tom Lane (tgl@sss.pgh.pa.us) wrote:
> Andrew Dunstan <andrew@dunslane.net> writes:
> > If you have a format string, what do you want to do with the bits of the
> > format that aren't field references?
>
> I was thinking of it as being strictly a field list.  I don't know
> whether it's really practical to borrow log_line_prefix's one-character
> names for the fields (for one thing, there would need to be names for
> all the existing CSV columns, not all of which equate to log_line_prefix
> escapes);

I'm not really happy about the idea that you can only get certain
information in a log file if you use CSV format.  I also don't know
that there's really any particular reason log_line_prefix's names
have to be one character.

> but in any case anything other than field references would be
> disallowed.  If you prefer to use a name list as the syntax that's fine
> with me.

I do like the idea of having just a field list though, to keep things
simple for the CSV users, and we could also pre-process the list into
flag variables or a bitmask or similar to be able to quickly check if a
certain field should be included or not.  I'm not really keen about how
log_line_prefix currently parses the direct user-provided syntax every
time; strikes me as inefficient.
Thanks,
    Stephen