st 6. 4. 2022 v 19:49 odesílatel Tom Lane <tgl@sss.pgh.pa.us> napsal:
It's not difficult to get psql to show you the current value of a single GUC --- "SHOW" does that fine, and it has tab completion support for the GUC name. However, I very often find myself resorting to the much more tedious
select * from pg_settings where name like '%foo%';
when I want to see some related parameters, or when I'm a bit fuzzy on the exact name of the parameter. Not only is this a lot of typing, but unless I'm willing to type even more to avoid using "*", I'll get a wall of mostly unreadable text, because pg_settings is far too wide and cluttered with low-grade information.
In the discussion about adding privileges for GUCs [1], there was a proposal to add a new psql backslash command to show GUCs, which could reduce this problem to something like
\dcp *foo*
It can be a good idea. I am not sure about \dcp. maybe \show can be better?
Regards
Pavel
(The version proposed there was not actually useful for this purpose because it was too narrowly focused on GUCs with privileges, but that's easily fixed.)
So does anyone else like this idea?
In detail, I'd imagine this command showing the name, setting, unit, and vartype fields of pg_setting by default, and if you add "+" then it should add the context field, as well as applicable privileges when server version >= 15. However, there's plenty of room for bikeshedding that list of columns, not to mention the precise name of the command. (I'm not that thrilled with "\dcp" myself, as it looks like it might be a sub-form of "\dc".) So I thought I'd solicit comments before working on a patch not after.
I view this as being at least in part mop-up for commit a0ffa885e, especially since a form of this was discussed in that thread. So I don't think it'd be unreasonable to push into v15, even though it's surely a new feature.
