Обсуждение: psql's describe command (for sequences) output improvement

<br /><p><font size="2">Hi all,<br /><br /> I have a patch which tries to improve the '\d some_sequence_name' command
outputin psql utility. Before sending the patch to pgsql-patches I just want to know your opinion whether the new
outputof the command is OK or it needs to be modified before sending it to pgsql-patches.<br /><br /> For comparison
purpose,here is the output of the '\d some_sequence_name' command:<br /><br /> -- Say we have created a sequence named
'test_seq'already as CREATE SEQUENCE test_seq.<br /><br /> --<br /> -- Output: before applying the patch.<br /> --<br
/>testdb=# \d test_seq;<br /> Sequence "public.test_seq"<br />     Column     |  Type  <br />
---------------+---------<br/>  sequence_name | name<br />  last_value    | bigint<br />  increment_by  | bigint<br />
 max_value    | bigint<br />  min_value     | bigint<br />  cache_value   | bigint<br />  log_cnt       | bigint<br />
 is_cycled    | boolean<br />  is_called     | boolean<br /><br /> --<br /> -- Output: after applying the patch.<br />
--<br/> testdb=# \d test_seq;<br />                                   Sequence "public.test_seq"<br />  last_value |
increment_by|      max_value      | min_value | cache_value | log_cnt | is_cycled | is_called<br />
------------+--------------+---------------------+-----------+-------------+---------+-----------+-----------<br/>
 1         | 1            | 9223372036854775807 | 1         | 1           | 1       | f         | f<br /><br /><br
/><br/> Thanks in advance for your feedback(s).<br /><br /> --<br /> Aftab.</font> 

Aftab Hussain wrote:
> In general, \d command is working perfectly for database objects.
> 
> For sequences, I think the current \d some_sequence command's output is
> displaying information which does not help the end user very much. Also
> isn't the newly display information (same as information provided by 'select
> * from test_seq;' statement) is/can-be-considered the metadata information
> about the sequences queried about (since for the returning sequences data we
> have nextval('...'), currval('...') functions)?

Yes, you are kind of right that \d on sequences provides unhelpful
output, but having it display the sequence values seems odd.  TODO has:
       o Have psql show current values for a sequence

Maybe \d+ sequence_name should add a column that shows the current
values:
test=> \d+ x          Sequence "public.x"    Column     |  Type   | Value |
Description---------------+---------+----------------------sequence_name | name    | x last_value    | bigint  | 1
increment_by | bigint  | max_value     | bigint  | min_value     | bigint  | cache_value   | bigint  | log_cnt       |
bigint | is_cycled     | boolean | is_called     | boolean |
 

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