Re: Improving psql \ds

On 09/10/12 03:53, Robert Haas wrote:
> On Mon, Oct 8, 2012 at 3:49 AM, Julien Tachoires <julmon@gmail.com> wrote:
>> 2012/10/8 Tom Lane <tgl@sss.pgh.pa.us>:
>>> Julien Tachoires <julmon@gmail.com> writes:
>>>> About \ds behaviour, I think to add 2 columns :
>>>> - 'LastValue'
>>>> - 'Increment'
>>> That would make the command a great deal slower, since it would have to
>>> access each sequence to get that info.  I don't object to adding such
>>> columns to \ds+, but I don't think it's a good idea to put them in the
>>> basic command.
>> Ok.
>>
>>> The other problem you're going to have here is that there is in fact no
>>> such command as "\ds" (nor "\ds+"); rather, it's a special case of
>>> \dtsvi.  As such, putting any relkind-specific info into the result is
>>> problematic.  I think you're going to have to invent a different command
>>> if you want there to be sequence-specific columns.
>> Yes, that's why I plan to create a new function listSequences() and
>> call it from src/bin/psql/command.c :
>> +       /* \d* commands */
>> +       else if (cmd[0] == 'd')
>> +       {
>> ...
>> +                       case 's':
>> +                               success = listSequences(pattern, show_verbose);
>> +                               break;
> What happens if the user does this:
>
> \dis
>
Hmm...

'According' to Terry Prachett,that is probably short hand for telling 
the backend to go to Hell = 'dis' is apparently another name for 'Hell'!
(In his book 'Truth', commander Vimes has a personal dis-organiser - as 
the 'dis-organiser' is run by a demon from Hell.)

Now back to more appropriate comments...