Re: Improving psql \ds

2012/10/8 Robert Haas <robertmhaas(at)gmail(dot)com>:
> On Mon, Oct 8, 2012 at 3:49 AM, Julien Tachoires <julmon(at)gmail(dot)com> wrote:
>> 2012/10/8 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:
>>> Julien Tachoires <julmon(at)gmail(dot)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, you're right, this is not a good idea.