Re: misleading error message in ProcessUtilitySlow T_CreateStatsStmt

On 29.08.25 14:48, Álvaro Herrera wrote:
> On 2025-Aug-29, jian he wrote:
>
>> On Fri, Aug 29, 2025 at 5:46 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
>>> WFM, although I think you could shorten it to "tables, materialized
>>> views, and foreign tables". We generally expect that partitioned
>>> tables are included when saying "tables", no? I'm not dead set on
>>> that either way, though.
>>
>> https://www.postgresql.org/docs/current/sql-copy.html
>> use "COPY TO can be used only with plain tables, not views, and does
>> not copy rows from child tables or child partitions"
>
> I'm inclined to think that we should only mention partitioned tables
> specifically when they for some reason deviate from what we do for
> regular tables, i.e., what Tom is saying. I don't think we've had an
> explicit, consistent rule for that thus far, so there may be places
> where we fail to follow it.
>
> Anyway, I have pushed the error message change.

I think this message is still wrong. The check doesn't even look at the
relation kind, which is what the message is implying. (If the message
were about relkinds, then it should use
errdetail_relkind_not_supported().) It checks that the from list entry
is a table name instead of some other thing like VALUES or JOIN. So it
should be something like

CREATE STATISTICS only supports plain table names in the FROM clause

The same could also be accomplished by changing the grammar from

FROM from_list

to

FROM qualified_name_list