Re: renameatt() can rename attribute of index, sequence, ...

2010/3/3 KaiGai Kohei <kaigai@ak.jp.nec.com>:
> (2010/03/03 14:26), Robert Haas wrote:
>> 2010/3/2 KaiGai Kohei<kaigai@ak.jp.nec.com>:
>>> Is it an expected behavior?
>>>
>>>   postgres=>  CREATE SEQUENCE s;
>>>   CREATE SEQUENCE
>>>   postgres=>  ALTER TABLE s RENAME sequence_name TO abcd;
>>>   ALTER TABLE
>>>
>>>   postgres=>  CREATE TABLE t (a int primary key, b text);
>>>   NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "t_pkey" for table "t"
>>>   CREATE TABLE
>>>   postgres=>  ALTER TABLE t_pkey RENAME a TO xyz;
>>>   ALTER TABLE
>>>
>>> The documentation says:
>>>   http://developer.postgresql.org/pgdocs/postgres/sql-altertable.html
>>>
>>>     :
>>>   RENAME
>>>     The RENAME forms change the name of a table (or an index, sequence, or view) or
>>>     the name of an individual column in a table. There is no effect on the stored data.
>>>
>>> It seems to me the renameatt() should check relkind of the specified relation, and
>>> raise an error if relkind != RELKIND_RELATION.
>>
>> Are we talking about renameatt() or RenameRelation()?  Letting
>> RenameRelation() rename whatever seems fairly harmless; renameatt(),
>> on the other hand, should probably refuse to allow this:
>>
>> CREATE SEQUENCE foo;
>> ALTER TABLE foo RENAME COLUMN is_cycled TO bob;
>>
>> ...because that's just weird.  Tables, indexes, and views make sense,
>> but the attributes of a sequence should be nailed down I think;
>> they're basically system properties.
>
> I'm talking about renameatt(), not RenameRelation().

OK.  Your original example was misleading because you had renameatt()
in the subject line but the actual SQL commands were renaming a whole
relation (which is a reasonable thing to do).

> If our perspective is these are a type of system properties, we should
> be able to reference these attributes with same name, so it is not harmless
> to allow renaming these attributes.
>
> I also agree that it makes sense to allow renaming attributes of tables
> and views. But I don't know whether it makes sense to allow it on indexs,
> like sequence and toast relations.

I would think not.

...Robert