Re: pg_hba_lookup function to get all matching pg_hba.conf entries

On Thu, Dec 31, 2015 at 10:47 AM, Haribabu Kommi
<kommi(dot)haribabu(at)gmail(dot)com> wrote:
> On Wed, Dec 30, 2015 at 9:48 PM, Shulgin, Oleksandr
> <oleksandr(dot)shulgin(at)zalando(dot)de> wrote:
>> On Wed, Dec 30, 2015 at 4:31 AM, Haribabu Kommi <kommi(dot)haribabu(at)gmail(dot)com>
>> wrote:
>>>
>>>
>>> Adding quotes to pg_hba_lookup function makes it different from others.
>>> The issues regarding the same is already discussed in [1].
>>>
>>> select a.database[1], b.datname from
>>> pg_hba_lookup('postgres','kommih','::1')
>>> as a, pg_database as b where a.database[1]
>>> = b.datname;
>>>
>>> The queries like above are not possible with quoted output. It is very
>>> rare that the
>>> pg_hba_lookup function used in join operations, but still it is better
>>> to provide
>>> data without quotes. so I reverted these changes in the attached latest
>>> patch.
>>
>>
>> That's a good point. I wonder that maybe instead of re-introducing quotes
>> we could somehow make the unquoted keywords that have special meaning stand
>> out, e.g:
>>
>> database | {$sameuser}
>> user_name | {$all}
>>
>> That should make it obvious which of the values are placeholders and doesn't
>> interfere with joining database or user catalogs (while I would call
>> "sameuser" a very unlikely name for a database, "all" might be not that
>> unlikely name for a user, e.g. someone called like "Albert L. Lucky" could
>> use that as a login name).
>
> It is not only the problem with joins, the following two cases works
> without quotes only.
> With quotes the query doesn't match with the database name.
>
> select * from pg_hba_lookup('Test', 'kommih','127.0.0.1') where
> database = '{"Test"}';
> select * from pg_hba_lookup('Test', 'kommih','127.0.0.1') where
> database = '{Test}';

Hi, Do you have any further comments on the patch that needs to be
taken care?

Regards,
Hari Babu
Fujitsu Australia