Re: misleading error message in ProcessUtilitySlow T_CreateStatsStmt

On 05.09.25 14:30, Peter Eisentraut wrote:
> 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@sss.pgh.pa.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

I propose the attached patch to fix this.  I think this restores the 
original meaning better.