Re: Re: proposal - psql: possibility to specify sort for describe commands, when size is printed

On Fri, Mar 10, 2017 at 6:06 PM, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
wrote:

> 2017-03-10 16:00 GMT+01:00 Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru>:
>
>> On Fri, Mar 10, 2017 at 5:16 PM, Stephen Frost <sfrost(at)snowman(dot)net>
>> wrote:
>>
>>> * Peter Eisentraut (peter(dot)eisentraut(at)2ndquadrant(dot)com) wrote:
>>> > On 2/24/17 16:32, Pavel Stehule wrote:
>>> > > set EXTENDED_DESCRIBE_SORT size_desc
>>> > > \dt+
>>> > > \l+
>>> > > \di+
>>> > >
>>> > > Possible variants: schema_table, table_schema, size_desc,
>>> size_asc
>>> >
>>> > I can see this being useful, but I think it needs to be organized a
>>> > little better.
>>> >
>>> > Sort key and sort direction should be separate settings.
>>> >
>>> > I'm not sure why we need to have separate settings to sort by schema
>>> > name and table name. But if we do, then we should support that for all
>>> > object types. I think maybe that's something we shouldn't get into
>>> > right now.
>>> >
>>> > So I would have one setting for sort key = {name|size} and on for sort
>>> > direction = {asc|desc}.
>>>
>>> Perhaps I'm trying to be overly cute here, but why not let the user
>>> simply provide a bit of SQL to be put at the end of the query?
>>>
>>> That is, something like:
>>>
>>> \pset EXTENDED_DESCRIBE_ORDER_LIMIT 'ORDER BY 5 DESC LIMIT 10'
>>>
>>
>> I think that's the question of usability. After all, one can manually
>> type corresponding SQL instead of \d* commands. However, it's quite
>> cumbersome to do this every time.
>> I found quite useful to being able to switch between different sortings
>> quickly. For instance, after seeing tables sorted by name, user can
>> require them sorted by size descending, then sorted by size ascending,
>> etc...
>> Therefore, I find user-defined SQL clause to be cumbersome. Even psql
>> variable itself seems to be cumbersome for me.
>> I would propose to add sorting as second optional argument to \d*
>> commands. Any thoughts?
>>
>
> This proposal was here already - maybe two years ago. The psql command
> parser doesn't allow any complex syntax - more - the more parameters in one
> psql commands is hard to remember, hard to read.
>

Could you please provide a link to this discussion. Probably working with
multiple parameters in psql commands require some rework, but that's
definitely doable.

> With my proposal, and patch I would to cover following use case. It is
> real case. Anytime when we used \dt+ in psql we needed sort by size desc.
> When we should to see a size, then the top is interesting. This case is not
> absolute, but very often, so I would to create some simple way, how to do
> some parametrization (really simple).
>

We could combine both approaches: add parameters to psql commands and add
psql DEFAULT_(SORT_COLUMNS|DIRECTION|LIMIT) parameters.

------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company