Re: Add pg_basetype() function to obtain a DOMAIN base type

Hi,

On 1/2/24 01:00, jian he wrote:
> On Mon, Dec 4, 2023 at 5:11 PM John Naylor <johncnaylorls(at)gmail(dot)com> wrote:
>>
>> On Thu, Sep 28, 2023 at 12:22 AM Alexander Korotkov
>> <aekorotkov(at)gmail(dot)com> wrote:
>>> The one thing triggering my perfectionism is that the patch does two
>>> syscache lookups instead of one.
>>
>> For an admin function used interactively, I'm not sure why that
>> matters? Or do you see another use case?
>
> I did a minor refactor based on v1-0001.
> I think pg_basetype should stay at "9.26.4. System Catalog Information
> Functions".
> So I placed it before pg_char_to_encoding.
> Now functions listed on "Table 9.73. System Catalog Information
> Functions" will look like alphabetical ordering.
> I slightly changed the src/include/catalog/pg_proc.dat.
> now it looks like very similar to pg_typeof
>
> src6=# \df pg_typeof
> List of functions
> Schema | Name | Result data type | Argument data types | Type
> ------------+-----------+------------------+---------------------+------
> pg_catalog | pg_typeof | regtype | "any" | func
> (1 row)
>
> src6=# \df pg_basetype
> List of functions
> Schema | Name | Result data type | Argument data types | Type
> ------------+-------------+------------------+---------------------+------
> pg_catalog | pg_basetype | regtype | "any" | func
> (1 row)
>
> v2-0001 is as is in the first email thread, 0002 is my changes based on v2-0001.

I think the patch(es) look reasonable, so just a couple minor comments.

1) We already have pg_typeof() function, so maybe we should use a
similar naming convention pg_basetypeof()?

2) I was going to suggest using "any" argument, just like pg_typeof, but
I see 0002 patch already does that. Thanks!

3) I think the docs probably need some formatting - wrapping lines (to
make it consistent with the nearby stuff) and similar stuff.

Other than that it looks fine to me. It's a simple patch, so if we can
agree on the naming I'll get it cleaned up and pushed.

regards

--
Tomas Vondra
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