Re: Add support to COMMENT ON CURRENT DATABASE

On 1/9/17 1:34 PM, Robert Haas wrote:
> On Fri, Jan 6, 2017 at 7:29 PM, Peter Eisentraut
> <peter(dot)eisentraut(at)2ndquadrant(dot)com> wrote:
>> On 1/3/17 11:52 PM, Ashutosh Bapat wrote:
>>> We will need to make CURRENT_DATABASE a reserved keyword. But I like
>>> this idea more than COMMENT ON CURRENT DATABASE.
>>
>> We already have the reserved key word CURRENT_CATALOG, which is the
>> standard spelling. But I wouldn't be bothered if we made
>> CURRENT_DATABASE somewhat reserved as well.
>
> Maybe I'm just lacking in imagination, but what's the argument against
> spelling it CURRENT DATABASE?

To achieve consistent support for specifying the current database, we
would need to change the grammar for every command involving databases.
And it would also set a precedent for similar commands, such as current
user/role. Plus support in psql, pg_dump, etc. would get more complicated.

Instead, it would be simpler to define a grammar symbol like

database_name: ColId | CURRENT_DATABASE

and make a small analogous change in objectaddress.c and you're done.

Compare rolespec in gram.y.

--
Peter Eisentraut http://www.2ndQuadrant.com/
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