pgsql: Improve default and empty privilege outputs in psql.

Started by Tom Laneabout 2 years ago4 messages
#1Tom Lane
tgl@sss.pgh.pa.us

Improve default and empty privilege outputs in psql.

Default privileges are represented as NULL::aclitem[] in catalog ACL
columns, while revoking all privileges leaves an empty aclitem[].
These two cases used to produce identical output in psql meta-commands
like \dp. Using something like "\pset null '(default)'" as a
workaround for spotting the difference did not work, because null
values were always displayed as empty strings by describe.c's
meta-commands.

This patch improves that with two changes:

1. Print "(none)" for empty privileges so that the user is able to
distinguish them from default privileges, even without special
workarounds.

2. Remove the special handling of null values in describe.c,
so that "\pset null" is honored like everywhere else.
(This affects all output from these commands, not only ACLs.)

The privileges shown by \dconfig+ and \ddp as well as the column
privileges shown by \dp are not affected by change #1, because the
respective aclitem[] is reset to NULL or deleted from the catalog
instead of leaving an empty array.

Erik Wienhold and Laurenz Albe

Discussion: /messages/by-id/1966228777.127452.1694979110595@office.mailbox.org

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/d1379ebf4c2d3d399e739966dbfa34e92a53b727

Modified Files
--------------
doc/src/sgml/ddl.sgml | 16 ++++++++++-
src/bin/psql/describe.c | 57 +++++++++-----------------------------
src/test/regress/expected/psql.out | 55 ++++++++++++++++++++++++++++++++++++
src/test/regress/sql/psql.sql | 32 +++++++++++++++++++++
4 files changed, 115 insertions(+), 45 deletions(-)

#2Christoph Berg
myon@debian.org
In reply to: Tom Lane (#1)
Re: pgsql: Improve default and empty privilege outputs in psql.

Re: Tom Lane

Improve default and empty privilege outputs in psql.

I'm sorry to report this when 17.0 has already been wrapped, but this
change is breaking `psql -l` against 9.3-or-earlier servers:

$ /usr/lib/postgresql/17/bin/psql
psql (17rc1 (Debian 17~rc1-1.pgdg+2), Server 9.3.25)
Geben Sie �help� f�r Hilfe ein.

postgres =# \set ECHO_HIDDEN on
postgres =# \l
/******* ANFRAGE ********/
SELECT
d.datname as "Name",
pg_catalog.pg_get_userbyid(d.datdba) as "Owner",
pg_catalog.pg_encoding_to_char(d.encoding) as "Encoding",
'libc' AS "Locale Provider",
d.datcollate as "Collate",
d.datctype as "Ctype",
NULL as "Locale",
NULL as "ICU Rules",
CASE WHEN pg_catalog.cardinality(d.datacl) = 0 THEN '(none)' ELSE pg_catalog.array_to_string(d.datacl, E'\n') END AS "Access privileges"
FROM pg_catalog.pg_database d
ORDER BY 1;
/************************/

FEHLER: 42883: Funktion pg_catalog.cardinality(aclitem[]) existiert nicht
ZEILE 10: CASE WHEN pg_catalog.cardinality(d.datacl) = 0 THEN '(none...
^
TIP: Keine Funktion stimmt mit dem angegebenen Namen und den Argumenttypen �berein. Sie m�ssen m�glicherweise ausdr�ckliche Typumwandlungen hinzuf�gen.
ORT: ParseFuncOrColumn, parse_func.c:299

The psql docs aren't really explicit about which old versions are
still supported, but there's some mentioning that \d should work back
to 9.2:

<para><application>psql</application> works best with servers of the same
or an older major version. Backslash commands are particularly likely
to fail if the server is of a newer version than <application>psql</application>
itself. However, backslash commands of the <literal>\d</literal> family should
work with servers of versions back to 9.2, though not necessarily with
servers newer than <application>psql</application> itself.

\l seems a tad more important even.

Christoph

#3Tom Lane
tgl@sss.pgh.pa.us
In reply to: Christoph Berg (#2)
Re: pgsql: Improve default and empty privilege outputs in psql.

Christoph Berg <myon@debian.org> writes:

Re: Tom Lane

Improve default and empty privilege outputs in psql.

I'm sorry to report this when 17.0 has already been wrapped, but this
change is breaking `psql -l` against 9.3-or-earlier servers:
FEHLER: 42883: Funktion pg_catalog.cardinality(aclitem[]) existiert nicht

Grumble. Well, if that's the worst bug in 17.0 we should all be
very pleased indeed ;-). I'll see about fixing it after the
release freeze lifts.

The psql docs aren't really explicit about which old versions are
still supported, but there's some mentioning that \d should work back
to 9.2:

Yes, that's the expectation. I'm sure we can think of a more
backwards-compatible way to test for empty datacl, though.

regards, tom lane

#4Tom Lane
tgl@sss.pgh.pa.us
In reply to: Tom Lane (#3)
1 attachment(s)
Re: pgsql: Improve default and empty privilege outputs in psql.

I wrote:

Yes, that's the expectation. I'm sure we can think of a more
backwards-compatible way to test for empty datacl, though.

Looks like the attached should be sufficient. As penance, I tried
all the commands in describe.c against 9.2 (or the oldest supported
server version), and none of them fail now.

regards, tom lane

Attachments:

fix-ACL-printing-for-old-servers.patchtext/x-diff; charset=us-ascii; name=fix-ACL-printing-for-old-servers.patchDownload
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index faabecbc76..6a36c91083 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -6678,7 +6678,7 @@ printACLColumn(PQExpBuffer buf, const char *colname)
 {
 	appendPQExpBuffer(buf,
 					  "CASE"
-					  " WHEN pg_catalog.cardinality(%s) = 0 THEN '%s'"
+					  " WHEN pg_catalog.array_length(%s, 1) = 0 THEN '%s'"
 					  " ELSE pg_catalog.array_to_string(%s, E'\\n')"
 					  " END AS \"%s\"",
 					  colname, gettext_noop("(none)"),