Re: Psql patch to show access methods info

I think I would like this feature to be in, but I'm not sure that the
shape is final yet. My points:

a) I don't see any use for \dA as presented; I think the \dA+ output is
useful. Therefore my preference would be that \dA presents what the
latest patch has as \dA+. I think we should leave \dA+ unimplemented
for now; maybe we can use some use for it later on.

b) I think \dAp should list the function used for each support proc. I
don't have any use for \dAp actually (I already said that upthread,
sorry for repeating myself), but I think that if we have it, then
showing only the proc number is pointless.

c) it would be damn handy if \dAf (maybe \dAf+) lists the datatypes that
each opfamily has opclasses for. Maybe make the output an array, like
{int4,int8,numeric,...} Something like [*] but somehow make it
prettier?

d) This one I'm unsure about: should we list the opfamily for each
opclass in \dAc? I'm not sure whether it's useful for anything.

[*]
SELECT DISTINCT am.amname AS "AM",
CASE
WHEN pg_catalog.pg_opfamily_is_visible(f.oid)
THEN format('%I', f.opfname)
ELSE format('%I.%I', n.nspname, f.opfname)
END AS "Operator family",
string_agg(format_type(c.opcintype, -1), ', ') as "Applicable types",
pg_catalog.pg_get_userbyid(f.opfowner) AS "Owner"

FROM pg_catalog.pg_opfamily f
LEFT JOIN pg_catalog.pg_am am on am.oid = f.opfmethod
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = f.opfnamespace
left join pg_catalog.pg_opclass c on (f.oid = c.opcfamily)
group by 1, 2, 4 ORDER BY 1, 2;

--
Álvaro Herrera https://www.2ndQuadrant.com/
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