Don't like getObjectDescription results for pg_amop/pg_amproc
I notice that for a pg_amop object, getObjectDescription does this:
/*------
translator: %d is the operator strategy (a number), the
first two %s's are data type names, the third %s is the
description of the operator family, and the last %s is the
textual form of the operator with arguments. */
appendStringInfo(&buffer, _("operator %d (%s, %s) of %s: %s"),
amopForm->amopstrategy,
format_type_be(amopForm->amoplefttype),
format_type_be(amopForm->amoprighttype),
opfam.data,
format_operator(amopForm->amopopr));
This might seem all right in isolation, but it produces completely horrid
results as soon as you plug it into some larger message. For example,
contrib_regression=# alter operator family gin__int_ops using gin drop operator 8 (integer[],integer[]);
ERROR: cannot drop operator 8 (integer[], integer[]) of operator family gin__int_ops for access method gin: <@(integer[],integer[]) because operator class gin__int_ops for access method gin requires it
HINT: You can drop operator class gin__int_ops for access method gin instead.
The colon seems like it ought to introduce a subsidiary sentence, but
it does not, and the reader is led off into the weeds trying to figure
out what connects to what.
I follow the point of trying to show the actual operator name, but
we gotta work harder on the presentation. Perhaps this would work:
appendStringInfo(&buffer, _("operator %d (%s, %s) (that is, %s) of %s"),
amopForm->amopstrategy,
format_type_be(amopForm->amoplefttype),
format_type_be(amopForm->amoprighttype),
format_operator(amopForm->amopopr),
opfam.data);
leading to
ERROR: cannot drop operator 8 (integer[], integer[]) (that is, <@(integer[],integer[])) of operator family gin__int_ops for access method gin because operator class gin__int_ops for access method gin requires it
Likewise for pg_amproc entries, of course.
Or maybe we're just being too ambitious here and we should discard some of
this information. I'm not really sure that the format_operator result
can be included without complete loss of intelligibility.
Thoughts? I'm particularly unclear on how any of this might translate
into other languages, though I doubt that the current text is giving
good guidance to translators.
regards, tom lane
On Thu, Aug 15, 2019 at 2:08 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Or maybe we're just being too ambitious here and we should discard some of
this information. I'm not really sure that the format_operator result
can be included without complete loss of intelligibility.Thoughts? I'm particularly unclear on how any of this might translate
into other languages, though I doubt that the current text is giving
good guidance to translators.
Can left and right types of pg_amop mismatch to those of pg_operatror?
It probably could for domains, any* types or something. But for
builtin opclasses they always match.
# select * from pg_amop amop join pg_operator op on op.oid =
amop.amopopr where amop.amoplefttype != op.oprleft or
amop.amoprighttype != op.oprright;
(0 rows)
Could we discard one pair of types from output?
------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
Alexander Korotkov <a.korotkov@postgrespro.ru> writes:
On Thu, Aug 15, 2019 at 2:08 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Or maybe we're just being too ambitious here and we should discard some of
this information. I'm not really sure that the format_operator result
can be included without complete loss of intelligibility.
Could we discard one pair of types from output?
Yeah, it would help to stop using format_operator and just print the
bare name of the operator. (format_operator can actually make things
a whole lot worse than depicted in my example, because it may insist
on schema-qualification and double-quoting.) In principle that could
be ambiguous ... but the pg_amop entry has already been identified fully,
and I don't think it needs to be part of the charter of this printout
to *also* identify the underlying operator with complete precision.
I'm still not sure how to cram the operator name into the output
without using a colon, though.
regards, tom lane