Re: createdb feature request

Richard Huxton <dev(at)archonet(dot)com> writes:
> Postfix has a useful utility called "postconf"
> postconf => display all settings
> postconf foo => display setting foo
> postconf -n => display non-standard config settings
> Other stuff too, see http://www.postfix.org/postconf.1.html

> Standard procedure for problems on the postfix list is to ask for "postconf
> -n" output before anything else.

Hmm. The SQL-ish way to do this would be

select name, setting, source from pg_settings
where setting != default_value;

The compiled-in default value for each GUC variable is available in the
GUC data structure, but pg_settings doesn't currently expose it.
Possibly we should add that.

You can almost do it today with

select name, setting, source from pg_settings
where source != 'default';

but this clutters the output a little with values that have been
explicitly set but are still equal to the default. For instance,
I get

regression=# select name, setting, source from pg_settings
regression-# where source != 'default';
name | setting | source
-----------------------+----------------+----------------------
fsync | off | command line
lc_collate | C | override
lc_ctype | C | override
lc_messages | C | database
lc_monetary | C | database
lc_numeric | C | database
lc_time | C | database
max_connections | 100 | configuration file
server_encoding | SQL_ASCII | override
shared_buffers | 1000 | configuration file
tcpip_socket | on | command line
TimeZone | EST5EDT | environment variable
transaction_isolation | read committed | override
transaction_read_only | off | override
(14 rows)

Not sure if it's worth any work to shorten that.

regards, tom lane