Thread: very long record lines in expanded psql output

In expanded mode psql calculates the width of the longest field in all the output rows,
and prints the header line according to it. This often results in record header wrapping
over several lines (see example below).

This huge record header is printed the same way before each record, even if all the fields
in current record are small and fit into terminal width. This often leads to situations
when record header occupies the entirety of the screen, for all records, even though there are
only a few records with huge fields in a record set.

Maybe we can avoid making the header line longer than terminal width for \pset border 0
and \pset border 1? We already have terminal width calculated. Please see attached a patch
with the proposed implementation.

Example output before the modification, in a terminal with a 100-column width:

$ psql template1 -c "\x on" -c "\pset border 1;" -c "select n, repeat('x', n) as long_column_name from
unnest(array[42,210])as n"
 
Expanded display is on.
Border style is 1.
─[ RECORD 1 ]────┬──────────────────────────────────────────────────────────────────────────────────
────────────────────────────────────────────────────────────────────────────────────────────────────
─────────────────────────────
n                │ 42
long_column_name │ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
─[ RECORD 2 ]────┼──────────────────────────────────────────────────────────────────────────────────
────────────────────────────────────────────────────────────────────────────────────────────────────
─────────────────────────────
n                │ 210
long_column_name │ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxx

And here's the same command after the patch:

$ psql template1 -c "\x on" -c "\pset border 1;" -c "select n, repeat('x', n) as long_column_name from
unnest(array[42,210])as n"
 
Expanded display is on.
Border style is 1.
─[ RECORD 1 ]────┬──────────────────────────────────────────────────────────────────────────────────
n                │ 42
long_column_name │ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
─[ RECORD 2 ]────┼──────────────────────────────────────────────────────────────────────────────────
n                │ 210
long_column_name │ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Best regards,
Platon Pronko

Hi!

pspg looks nice :)

> Your proposal breaks pspg
> 
> https://github.com/okbob/pspg

I tried the following (after the patch):

./psql template1 -c "select n, repeat('x', n) as long_column_name from unnest(array[42,210]) as n" | pspg

And it seems that pspg handled the situation without any issue. Also I tried inserting newlines into the output, and
pspgstill performed without issue. Can you give an example of scenario which should break after changing the record
headerlength?
 

Best regards,
Platon Pronko

Hi!

> a) with line cursor

Tried in different configurations, seems that line cursor works fine.

> b) format detection - I try to detect the header line - and I expect this
> line has the most length of all lines. I use a line with the same length as
> the column's type info (data, border).

I looked at pspg source, and here's what I found (please correct me if some/all
of my assumptions are wrong):

1. Input handling and format detection happens in table.c readfile().

2. There's some variables in DataDesc - maxx and maxbytes - that store the
longest line seen so far. But they are re-updated on each new row, so the fact
that header is shorter shouldn't affect them.

3. Expanded header detection is handled by is_expanded_header function. It has
ei_minx and ei_maxx return pointers, but when it is used from readfile() these
pointers are set to NULL in both cases - so header length is simply ignored.

> Did you test the wrapped format? It is working
> 
> \pset format wrapped
> \x
> select  * from pg_class;

There's no difference in outputs in wrapped format, so pspg behavior is also unaffected.

By the way, it seems that pspg recommends setting \pset border 2 anyway, so in vast
majority of cases there should be no possibility of difference at all - proposed patch
doesn't change output for \pset border 2 (because there's no sane way of making it
look okay in presence of long fields anyway).

Best regards,
Platon Pronko

Hi!

My apologies - I was using pspg incorrectly. If it's called via the pipe
then all the column wrapping is ignored, and that's why I couldn't reproduce
the issues. If instead pspg is used via "\setenv PAGER pspg", then I indeed can't
scroll the table horizontally more than 1 character, and that's definitely
broken.

I'll be using "\pset format wrapped" from now on, it's good enough. My only
issue would be with copying the long cell contents, but that's an uncommon
case and can be worked around without too much trouble.

Best regards,
Platon Pronko

Hi!

> pspg supports copy cell to clipboard - you can copy complete cell
> 
> but I am not sure if it is working well in extended mode. This mode is not
> extra tested in pspg

Thanks for the tip!

I tried it out, in non-extended mode copy indeed works well, in extended mode vertical cursor
selects both columns (and copies both), and in extended+wrapped mode copy includes wrapping
symbol.

Best regards,
Platon Pronko

On 8/5/21 6:56 AM, Pavel Stehule wrote:
> Hi
>
> čt 5. 8. 2021 v 12:36 odesílatel Platon Pronko
> <platon7pronko@gmail.com <mailto:platon7pronko@gmail.com>> napsal:
>
>     In expanded mode psql calculates the width of the longest field in
>     all the output rows,
>     and prints the header line according to it. This often results in
>     record header wrapping
>     over several lines (see example below).
>
>     This huge record header is printed the same way before each
>     record, even if all the fields
>     in current record are small and fit into terminal width. This
>     often leads to situations
>     when record header occupies the entirety of the screen, for all
>     records, even though there are
>     only a few records with huge fields in a record set.
>
>     Maybe we can avoid making the header line longer than terminal
>     width for \pset border 0
>     and \pset border 1? We already have terminal width calculated.
>     Please see attached a patch
>     with the proposed implementation.
>
>     Example output before the modification, in a terminal with a
>     100-column width:
>
>     $ psql template1 -c "\x on" -c "\pset border 1;" -c "select n,
>     repeat('x', n) as long_column_name from unnest(array[42,210]) as n"
>     Expanded display is on.
>     Border style is 1.
>     ─[ RECORD 1
>     ]────┬──────────────────────────────────────────────────────────────────────────────────
>     ────────────────────────────────────────────────────────────────────────────────────────────────────
>     ─────────────────────────────
>     n                │ 42
>     long_column_name │ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>     ─[ RECORD 2
>     ]────┼──────────────────────────────────────────────────────────────────────────────────
>     ────────────────────────────────────────────────────────────────────────────────────────────────────
>     ─────────────────────────────
>     n                │ 210
>     long_column_name │
>     xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>     xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>     xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
>     And here's the same command after the patch:
>
>     $ psql template1 -c "\x on" -c "\pset border 1;" -c "select n,
>     repeat('x', n) as long_column_name from unnest(array[42,210]) as n"
>     Expanded display is on.
>     Border style is 1.
>     ─[ RECORD 1
>     ]────┬──────────────────────────────────────────────────────────────────────────────────
>     n                │ 42
>     long_column_name │ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>     ─[ RECORD 2
>     ]────┼──────────────────────────────────────────────────────────────────────────────────
>     n                │ 210
>     long_column_name │
>     xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>     xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>     xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
>
> the length of lines should be consistent.
>
> Your proposal breaks pspg
>
> https://github.com/okbob/pspg <https://github.com/okbob/pspg>
>
> It can be separate option, but it should not be default
>
>


I also find this annoying and would be happy to be rid of it.  I could
see setting an option like


\pset xheader_width column|page|nnn


cheers


andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com

Hi!

> I also find this annoying and would be happy to be rid of it.

Have you tried "\pset format wrapped"? Pavel suggested it, and it solved most of the problem for me, for example.

Best regards,
Platon Pronko

On 8/5/21 12:04 PM, Platon Pronko wrote:
> Hi!
>
>> I also find this annoying and would be happy to be rid of it.
>
> Have you tried "\pset format wrapped"? Pavel suggested it, and it
> solved most of the problem for me, for example.


Yes, but it changes the data line output. Ideally, you should be able
to  modify these independently.


cheers


andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com

Hi!
>>> I also find this annoying and would be happy to be rid of it.
>>
>> Have you tried "\pset format wrapped"? Pavel suggested it, and it
>> solved most of the problem for me, for example.
> 
> Yes, but it changes the data line output. Ideally, you should be able
> to  modify these independently.

I agree, and I think this can be implemented, but I'm a bit afraid of
introducing an additional psql option (there's already quite a lot of them).
I suspect primary PostgreSQL maintainers won't be happy with such an approach.

Best regards,
Platon Pronko

Hi!

>>>>> I also find this annoying and would be happy to be rid of it.
>>>>
>>>> Have you tried "\pset format wrapped"? Pavel suggested it, and it
>>>> solved most of the problem for me, for example.
>>>
>>> Yes, but it changes the data line output. Ideally, you should be able
>>> to  modify these independently.
>>
>> I agree, and I think this can be implemented, but I'm a bit afraid of
>> introducing an additional psql option (there's already quite a lot of
>> them).
>> I suspect primary PostgreSQL maintainers won't be happy with such an
>> approach.
>>
> 
> it can be a fully new format - designed for simple copy from terminal. Some
> like
> 
> ====== record: 10 ======
> ------------ proname ------------
> left
> ------------ prosrc  ------------
> $lalalal
> ewqrwqerw
> ewqrwqerqrewq
> $
> ===============

I don't think that would be a good idea. If somebody really just needs to copy,
then wrapping the query in "copy (...) to stdout" already works nicely,
no need to create a special mode just for that.
I think the question was more about being able to copy in an ad-hoc way,
in the middle of scrolling trough "normal" output.

Best regards,
Platon Pronko

Hi!

>> I don't think that would be a good idea. If somebody really just needs to
>> copy,
>> then wrapping the query in "copy (...) to stdout" already works nicely,
>> no need to create a special mode just for that.
>>
> 
> It is working well, but it is copy to file, not copy to clipboard.

Maybe I misunderstood - are you suggesting this a special mode in pspg? I thought
that you were suggesting to implement a mode in psql, something like
"\pset format_for_clipboard".
  
>> I think the question was more about being able to copy in an ad-hoc way,
>> in the middle of scrolling trough "normal" output.
> 
> I understand your motivation, but I don't feel a significant benefit to
> increase the complexity of the main format (more, when it breaks pspg,
> without possibility to fix it). but it can depend on usual data, and it is
> true, so when I use pspg, I don't use extended mode too often.

To clarify: I'm not suggesting my patch anymore - it definitely breaks pspg and this
is completely unacceptable.
We're just discussing the possible alternate solutions, I think.

Best regards,
Platon Pronko

> it can be a fully new format - designed for simple copy from terminal. Some
> like
> 
> ====== record: 10 ======
> ------------ proname ------------
> left
> ------------ prosrc  ------------
> $lalalal
> ewqrwqerw
> ewqrwqerqrewq
> $
> ===============

> no, it was proposed for psql

How is this better than "copy (...) to stdout"? E.g.:

$ copy (select * from pg_class limit 1) to stdout;
2619    pg_statistic    11    12016    0    10    2    2619    0    18    402    18    2840    t    f    p    r    31
0    f    f    f    f    f    t    n    f0    478    1    {postgres=arwdDxt/postgres}    \N    \N
 

You can still copy the necessary parts (using mouse selection) -
seems that it achieves the the same goal.

Best regards,
Platon Pronko

Platon Pronko wrote:

> Maybe we can avoid making the header line longer than terminal width
> for \pset border 0 and \pset border 1? We already have terminal
> width calculated. Please see attached a patch with the proposed
> implementation.

+1 for doing something against these long lines.

Rather than padding up to the terminal's width, we could simply end
the line after the "-[RECORD N]-" marker, with the idea that the
rest of it does not add much to readability anyway.
And when writing into a file as opposed to a terminal, getting rid of
these lines is useful too.

In that case, your example could be displayed like this:

=> \pset expanded on
=> \pset border 1

=> select n, repeat('x', n) as long_column_name from unnest(array[42,210])
 as n;

-[ RECORD 1 ]-
n         | 42
long_column_name | xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
-[ RECORD 2 ]-
n         | 210
long_column_name |

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

=> \pset border 0
=> select n, repeat('x', n) as long_column_name from unnest(array[42,210])
 as n;

* Record 1
n         42
long_column_name xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
* Record 2
n         210
long_column_name

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx



Best regards,
--
Daniel Vérité
PostgreSQL-powered mailer: https://www.manitou-mail.org
Twitter: @DanielVerite

On 8/5/21 2:25 PM, Pavel Stehule wrote:
>
>
> čt 5. 8. 2021 v 18:48 odesílatel Platon Pronko
> <platon7pronko@gmail.com <mailto:platon7pronko@gmail.com>> napsal:
>
>     Hi!
>     >>> I also find this annoying and would be happy to be rid of it.
>     >>
>     >> Have you tried "\pset format wrapped"? Pavel suggested it, and it
>     >> solved most of the problem for me, for example.
>     >
>     > Yes, but it changes the data line output. Ideally, you should be
>     able
>     > to  modify these independently.
>
>     I agree, and I think this can be implemented, but I'm a bit afraid of
>     introducing an additional psql option (there's already quite a lot
>     of them).
>     I suspect primary PostgreSQL maintainers won't be happy with such
>     an approach.
>
>
> it can be a fully new format - designed for simple copy from terminal.
> Some like
>
> ====== record: 10 ======
> ------------ proname ------------
> left
> ------------ prosrc  ------------
> $lalalal
> ewqrwqerw
> ewqrwqerqrewq
> $
> ===============
>
>

I think that's really a different idea. The original proposal was simply
to deal with insanely long header lines. This seems like massive scope
creep.


cheers


andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com

On 8/5/21 12:48 PM, Platon Pronko wrote:
> Hi!
>>>> I also find this annoying and would be happy to be rid of it.
>>>
>>> Have you tried "\pset format wrapped"? Pavel suggested it, and it
>>> solved most of the problem for me, for example.
>>
>> Yes, but it changes the data line output. Ideally, you should be able
>> to  modify these independently.
>
> I agree, and I think this can be implemented, but I'm a bit afraid of
> introducing an additional psql option (there's already quite a lot of
> them).
> I suspect primary PostgreSQL maintainers won't be happy with such an
> approach.
>
>

I think I qualify as one of those ... :-)


cheers


andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com

Hi!

>>>>> I also find this annoying and would be happy to be rid of it.
>>>>
>>>> Have you tried "\pset format wrapped"? Pavel suggested it, and it
>>>> solved most of the problem for me, for example.
>>>
>>> Yes, but it changes the data line output. Ideally, you should be able
>>> to  modify these independently.
>>
>> I agree, and I think this can be implemented, but I'm a bit afraid of
>> introducing an additional psql option (there's already quite a lot of
>> them).
>> I suspect primary PostgreSQL maintainers won't be happy with such an
>> approach.
>>
>>
> 
> I think I qualify as one of those ... :-)

Sorry, I'm new here, don't know who's who :)

I'll start working on a new patch then. A couple questions about specifics:

1. Can we add "expanded" in the option name, like "xheader_expanded_width"?
I think adjusting the header row width doesn't make sense on any other modes,
and placing that in the option name makes intent a bit clearer.

2. What was "column" option in your original suggestion supposed to do?
("\pset xheader_width column|page|nnn")

3. Should we bother with using this option when in "\pset border 2" mode?
I can do it for consistency, but it will still look bad.

Best regards,
Platon Pronko

On 8/7/21 10:56 AM, Platon Pronko wrote:
> Hi!
>
>>>>>> I also find this annoying and would be happy to be rid of it.
>>>>>
>>>>> Have you tried "\pset format wrapped"? Pavel suggested it, and it
>>>>> solved most of the problem for me, for example.
>>>>
>>>> Yes, but it changes the data line output. Ideally, you should be able
>>>> to  modify these independently.
>>>
>>> I agree, and I think this can be implemented, but I'm a bit afraid of
>>> introducing an additional psql option (there's already quite a lot of
>>> them).
>>> I suspect primary PostgreSQL maintainers won't be happy with such an
>>> approach.
>>>
>>>
>>
>> I think I qualify as one of those ... :-)
>
> Sorry, I'm new here, don't know who's who :)


No problem. Welcome! We're always very glad to see new contributors.


>
> I'll start working on a new patch then. A couple questions about
> specifics:
>
> 1. Can we add "expanded" in the option name, like
> "xheader_expanded_width"?
> I think adjusting the header row width doesn't make sense on any other
> modes,
> and placing that in the option name makes intent a bit clearer.



"xheader" was meant to be shorthand for "expanded output header"


>
> 2. What was "column" option in your original suggestion supposed to do?
> ("\pset xheader_width column|page|nnn")


It's meant to say don't print anything past the column spec, e.g.:


-[ RECORD 1 ]----+
n                | 42
long_column_name | xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
-[ RECORD 2 ]----+
n                | 210
long_column_name |
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx


>
> 3. Should we bother with using this option when in "\pset border 2" mode?
> I can do it for consistency, but it will still look bad.
>
>

Probably not, but since I never use it I'll let others who do weigh in
on the subject.


cheers


andrew


--
Andrew Dunstan
EDB: https://www.enterprisedb.com

Hi!

Please find attached the patch implementing the proposed changes.
I hope I didn't forget anything (docs, tab completion, comments, etc),
if I did forget something please tell me and I'll fix it.

Best regards,
Platon Pronko

On 2021-08-08 01:18, Andrew Dunstan wrote:
> 
> On 8/7/21 10:56 AM, Platon Pronko wrote:
>> Hi!
>>
>>>>>>> I also find this annoying and would be happy to be rid of it.
>>>>>>
>>>>>> Have you tried "\pset format wrapped"? Pavel suggested it, and it
>>>>>> solved most of the problem for me, for example.
>>>>>
>>>>> Yes, but it changes the data line output. Ideally, you should be able
>>>>> to  modify these independently.
>>>>
>>>> I agree, and I think this can be implemented, but I'm a bit afraid of
>>>> introducing an additional psql option (there's already quite a lot of
>>>> them).
>>>> I suspect primary PostgreSQL maintainers won't be happy with such an
>>>> approach.
>>>>
>>>>
>>>
>>> I think I qualify as one of those ... :-)
>>
>> Sorry, I'm new here, don't know who's who :)
> 
> 
> No problem. Welcome! We're always very glad to see new contributors.
> 
> 
>>
>> I'll start working on a new patch then. A couple questions about
>> specifics:
>>
>> 1. Can we add "expanded" in the option name, like
>> "xheader_expanded_width"?
>> I think adjusting the header row width doesn't make sense on any other
>> modes,
>> and placing that in the option name makes intent a bit clearer.
> 
> 
> 
> "xheader" was meant to be shorthand for "expanded output header"
> 
> 
>>
>> 2. What was "column" option in your original suggestion supposed to do?
>> ("\pset xheader_width column|page|nnn")
> 
> 
> It's meant to say don't print anything past the column spec, e.g.:
> 
> 
> -[ RECORD 1 ]----+
> n                | 42
> long_column_name | xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> -[ RECORD 2 ]----+
> n                | 210
> long_column_name |
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> 
> 
>>
>> 3. Should we bother with using this option when in "\pset border 2" mode?
>> I can do it for consistency, but it will still look bad.
>>
>>
> 
> Probably not, but since I never use it I'll let others who do weigh in
> on the subject.
> 
> 
> cheers
> 
> 
> andrew
> 
> 
> --
> Andrew Dunstan
> EDB: https://www.enterprisedb.com
> 

Hi!

Apparently I did forget something, and that's the patch itself :)
Thanks for Justin Pryzby for pointing this out.

Attaching the patch now.

Best regards,
Platon Pronko

On 2021-08-23 20:51, Platon Pronko wrote:
> Hi!
> 
> Please find attached the patch implementing the proposed changes.
> I hope I didn't forget anything (docs, tab completion, comments, etc),
> if I did forget something please tell me and I'll fix it.
> 
> Best regards,
> Platon Pronko
> 
> On 2021-08-08 01:18, Andrew Dunstan wrote:
>>
>> On 8/7/21 10:56 AM, Platon Pronko wrote:
>>> Hi!
>>>
>>>>>>>> I also find this annoying and would be happy to be rid of it.
>>>>>>>
>>>>>>> Have you tried "\pset format wrapped"? Pavel suggested it, and it
>>>>>>> solved most of the problem for me, for example.
>>>>>>
>>>>>> Yes, but it changes the data line output. Ideally, you should be able
>>>>>> to  modify these independently.
>>>>>
>>>>> I agree, and I think this can be implemented, but I'm a bit afraid of
>>>>> introducing an additional psql option (there's already quite a lot of
>>>>> them).
>>>>> I suspect primary PostgreSQL maintainers won't be happy with such an
>>>>> approach.
>>>>>
>>>>>
>>>>
>>>> I think I qualify as one of those ... :-)
>>>
>>> Sorry, I'm new here, don't know who's who :)
>>
>>
>> No problem. Welcome! We're always very glad to see new contributors.
>>
>>
>>>
>>> I'll start working on a new patch then. A couple questions about
>>> specifics:
>>>
>>> 1. Can we add "expanded" in the option name, like
>>> "xheader_expanded_width"?
>>> I think adjusting the header row width doesn't make sense on any other
>>> modes,
>>> and placing that in the option name makes intent a bit clearer.
>>
>>
>>
>> "xheader" was meant to be shorthand for "expanded output header"
>>
>>
>>>
>>> 2. What was "column" option in your original suggestion supposed to do?
>>> ("\pset xheader_width column|page|nnn")
>>
>>
>> It's meant to say don't print anything past the column spec, e.g.:
>>
>>
>> -[ RECORD 1 ]----+
>> n                | 42
>> long_column_name | xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>> -[ RECORD 2 ]----+
>> n                | 210
>> long_column_name |
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>>
>>
>>>
>>> 3. Should we bother with using this option when in "\pset border 2" mode?
>>> I can do it for consistency, but it will still look bad.
>>>
>>>
>>
>> Probably not, but since I never use it I'll let others who do weigh in
>> on the subject.
>>
>>
>> cheers
>>
>>
>> andrew
>>
>>
>> -- 
>> Andrew Dunstan
>> EDB: https://www.enterprisedb.com
>>

On 8/23/21 2:00 PM, Platon Pronko wrote:
> Hi!
>
> Apparently I did forget something, and that's the patch itself :)
> Thanks for Justin Pryzby for pointing this out.
>
> Attaching the patch now.
>
>

Please add it to the commitfest, the next one starts in about a week.


cheers


andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com

Hi!

Done, here's the link: https://commitfest.postgresql.org/34/3295/

Best regards,
Platon Pronko

On 2021-08-23 21:14, Andrew Dunstan wrote:
> 
> On 8/23/21 2:00 PM, Platon Pronko wrote:
>> Hi!
>>
>> Apparently I did forget something, and that's the patch itself :)
>> Thanks for Justin Pryzby for pointing this out.
>>
>> Attaching the patch now.
>>
>>
> 
> Please add it to the commitfest, the next one starts in about a week.
> 
> 
> cheers
> 
> 
> andrew
> 
> --
> Andrew Dunstan
> EDB: https://www.enterprisedb.com
> 

On 8/23/21 2:00 PM, Platon Pronko wrote:
> Hi!
>
> Apparently I did forget something, and that's the patch itself :)
> Thanks for Justin Pryzby for pointing this out.
>
> Attaching the patch now.
>
>

(Please avoid top-posting on PostgreSQL lists)


This patch seems basically sound. A couple of things:


1. It's not following project indentation style (BSD brace placement)

2. It would possibly be better to pass the relevant parts of the options
to print_aligned_vertical_line() rather than the whole options
structure. It feels odd to pass both that and opt_border.


cheers


andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com

On 2021-09-23 22:28, Andrew Dunstan wrote:
>
> 2. It would possibly be better to pass the relevant parts of the options
> to print_aligned_vertical_line() rather than the whole options
> structure. It feels odd to pass both that and opt_border.

What do you think about doing it the other way around - passing only whole
options structure? That way we will roll 4 parameters (opt_border, printTextFormat,
and two xheader ones) into only one argument.
This increases code coupling a bit, but I'm not sure if that's relevant here.

Best regards,
Platon Pronko

On 9/24/21 12:49 AM, Platon Pronko wrote:
> On 2021-09-23 22:28, Andrew Dunstan wrote:
>>
>> 2. It would possibly be better to pass the relevant parts of the options
>> to print_aligned_vertical_line() rather than the whole options
>> structure. It feels odd to pass both that and opt_border.
>
> What do you think about doing it the other way around - passing only
> whole
> options structure? That way we will roll 4 parameters (opt_border,
> printTextFormat,
> and two xheader ones) into only one argument.
> This increases code coupling a bit, but I'm not sure if that's
> relevant here.
>

Sure, as long as it doesn't result in duplicated computation.


cheers


andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com

On 2021-09-24 14:42, Andrew Dunstan wrote:
> 
> On 9/24/21 12:49 AM, Platon Pronko wrote:
>> On 2021-09-23 22:28, Andrew Dunstan wrote:
>>>
>>> 2. It would possibly be better to pass the relevant parts of the options
>>> to print_aligned_vertical_line() rather than the whole options
>>> structure. It feels odd to pass both that and opt_border.
>>
>> What do you think about doing it the other way around - passing only
>> whole
>> options structure? That way we will roll 4 parameters (opt_border,
>> printTextFormat,
>> and two xheader ones) into only one argument.
>> This increases code coupling a bit, but I'm not sure if that's
>> relevant here.
>>
> 
> Sure, as long as it doesn't result in duplicated computation.

Hi!

Please find attached the updated patch - with fixed braces and
adjusted parameters to print_aligned_vertical_line().

Best regards,
Platon Pronko

> Hi,
> 
> +               pg_log_error("\\pset: allowed xheader_width values are full
> (default), column, page, or an number specifying exact width.");
> 
>   an number specifying -> a number specifying
> 
> Cheers
> 

Fixed, attaching the updated patch. Thank you!

Best regards,
Platon Pronko

On 2021-10-03 Su 16:03, Platon Pronko wrote:
>> Hi,
>>
>> +               pg_log_error("\\pset: allowed xheader_width values
>> are full
>> (default), column, page, or an number specifying exact width.");
>>
>>   an number specifying -> a number specifying
>>
>> Cheers
>>
>
> Fixed, attaching the updated patch. Thank you!
>
>

Committed. There were a couple of bits missing, which I filled in, and I
changed the behaviour when the option is given without an argument, so
that instead of resetting it the current value is shown, similarly to
how most pset options work.


cheers


andrew


--
Andrew Dunstan
EDB: https://www.enterprisedb.com

Re: Andrew Dunstan
> >> +               pg_log_error("\\pset: allowed xheader_width values are full
> >> (default), column, page, or an number specifying exact width.");

> Committed. There were a couple of bits missing, which I filled in, and I
> changed the behaviour when the option is given without an argument, so
> that instead of resetting it the current value is shown, similarly to
> how most pset options work.

Thanks for implementing this! This has been #1 on my PG annoyances
list since forever. I had even tried to patch it 10½ years ago, but
ever managed to get that patch to submittable quality.

Now, is there a chance that we could make this the default? Having
psql print a whole screen of ------------ minus characters doesn't
seem very useful as default behavior.

I see upthread that Pavel was objecting to that because pspg doesn't
understand it. But since the expanded format is a one-column output,
and the only thing pspg needs to know is the maxium line length, I'd
think pspg could just look at each line, and update the maximum as it
reads the input anyway.

Can we set 'page' as default?

Christoph

Re: Pavel Stehule
> pspg requires all lines to have the same width. It can do some corrections
> - but it is hard to detect wanted differences or just plain text format.
> 
> can be nice to have the first invisible row with some information about
> used formatting. pspg does some heuristic but this code is not nice and it
> is fragile.

I like pspg and use it myself, but I don't think a tool that does the
right thing by hiding a full screen of ---- from the user should
hinder making the same progress in psql with a simple pager.

Christoph

On 2022-08-30 Tu 10:55, Pavel Stehule wrote:
>
>
> út 30. 8. 2022 v 16:49 odesílatel Pavel Stehule
> <pavel.stehule@gmail.com> napsal:
>
>
>
>     út 30. 8. 2022 v 16:36 odesílatel Christoph Berg <myon@debian.org>
>     napsal:
>
>         Re: Pavel Stehule
>         > pspg requires all lines to have the same width. It can do
>         some corrections
>         > - but it is hard to detect wanted differences or just plain
>         text format.
>         >
>         > can be nice to have the first invisible row with some
>         information about
>         > used formatting. pspg does some heuristic but this code is
>         not nice and it
>         > is fragile.
>
>         I like pspg and use it myself, but I don't think a tool that
>         does the
>         right thing by hiding a full screen of ---- from the user should
>         hinder making the same progress in psql with a simple pager.
>
>
>     ASCII allows to set some metadata, that should be invisible in all
>     correctly implemented pagers.
>
>
> or these parameters can be sent by pager's command line or via some
> environment variable. Currently there are only two pagers on the world
> that support tabular format, and both are created against psql (pspg
> and ov), so we can define our own protocol. Surely - pspg will have
> heuristic forever, because I want to support psql, mysql and many
> others. But it can be fine to switch to some more robust mode. It can
> be interesting for continuous load via pipe.  
>

I'm somewhat sympathetic to Christoph's position.

Surely pspg could itself issue

   \pset xheader_width full

at the start of a session.


cheers


andrew

-- 

Andrew Dunstan
EDB: https://www.enterprisedb.com

On 2022-Jul-25, Andrew Dunstan wrote:

> Committed. There were a couple of bits missing, which I filled in, and I
> changed the behaviour when the option is given without an argument, so
> that instead of resetting it the current value is shown, similarly to
> how most pset options work.

I was translating the new messages introduced by this commit, and
decided to unify them.  While doing so, I notice that the feature
misbehaves when you give it a string value that doesn't match any valid
value: it just resets the value to 0, which is entirely the wrong thing.
For other settings, we first verify that the given value is valid, and
only then we change the setting.

So I came up with the attached.  While at it, I noticed that we have
other uses of atoi() there, most notably pager_min_lines.  My first
impulse was to just to do the same as for xheader_width, namely to test
whether the atoid result is zero, and not change in that case.  But then
I noticed we're already using variables.c facilities, so I decided to do
likewise; this results in simpler code.  So we're now stricter, because
variables.c rejects trailing junk after the number.  (123asd was
previously parsed as 123, now it's an error.)


There remain atoi uses in this code, and aside from the atoi()-induced
behavior of making any non-number input set it to 0, it does stuff like

=# \pset border 65538asd
Border style is 2.

because border style is short int, so this value overflows it.  Same
happens with 'columns'.  However, this is all very old code and nobody
seems to have complained.

-- 
Álvaro Herrera               48°01'N 7°57'E  —  https://www.EnterpriseDB.com/
"¿Cómo puedes confiar en algo que pagas y que no ves,
y no confiar en algo que te dan y te lo muestran?" (Germán Poo)