Re: VIP: new format for psql - shell - simple using psql in shell

2012/5/26 Tom Lane <tgl@sss.pgh.pa.us>:
> Bruce Momjian <bruce@momjian.us> writes:
>> On Sat, May 26, 2012 at 05:39:23PM +0200, Pavel Stehule wrote:
>>> I proposed new psql's format "shell". This format is optimized for
>>> processing returned result in shell:
>
>> I am unclear exactly how this relates to shells.
>
> What I'm unclear on is why we'd want to encourage that style of
> programming.  The most charitable prediction of performance is that it
> would suck --- not only do you have all the inefficiencies inherent in
> row-by-row result processing with a shell script, but you're forcing a
> separate database connection for each query.  And I don't actually see
> where it would be especially convenient to use, compared to say perl
> or python or other scripting languages.  I'd rather see us worrying
> about the convenience of cases like
>
>        psql ... | perl -e ...

A performance is not important in this case - typical use case for
this feature are simple tasks - some simple maintaining - where people
can prepare SQL in psql, and later can reuse knowledge in some simple
scripts. Shell has one significant advantage against perl or python -
is everywhere (on UNIX) and it is best for very simple tasks.

Regards

Pavel



>
>                        regards, tom lane