[DISCUSSION] Describe complex columns

[Shreelekhya]

Hi,

Currently describe formatted displays the column information of a table and
some additional information. When complex types such as  ARRAY, STRUCT, and
MAP types are present in table, column definition can be long and it’s
difficult to read in a nested format.

For complex types available, the DESCRIBE output can be formatted to avoid
long lines for multiple fields. We can pass the complex field name to the
command and visualize its structure as if were a table.

DDL Commands:
DESCRIBE fieldname ON [db_name.]table_name;
DESCRIBE short [db_name.]table_name;

Please let me know your valid inputs about the same.
Following is the link to the design document.

https://docs.google.com/document/d/1uNCByKR09Up9S2hpiEXYDA8XXIEZ2jI9PMSzMIVJ0Js/edit?usp=sharing


Thanks,
Shreelekhya



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[kunalkapoor]

+1 good idea for visualizing complex columns

On Thu, Mar 18, 2021 at 10:35 PM Shreelekhya <[hidden email]>
wrote:

> Hi,
>
> Currently describe formatted displays the column information of a table and
> some additional information. When complex types such as  ARRAY, STRUCT, and
> MAP types are present in table, column definition can be long and it’s
> difficult to read in a nested format.
>
> For complex types available, the DESCRIBE output can be formatted to avoid
> long lines for multiple fields. We can pass the complex field name to the
> command and visualize its structure as if were a table.
>
> DDL Commands:
> DESCRIBE fieldname ON [db_name.]table_name;
> DESCRIBE short [db_name.]table_name;
>
> Please let me know your valid inputs about the same.
> Following is the link to the design document.
>
>
> https://docs.google.com/document/d/1uNCByKR09Up9S2hpiEXYDA8XXIEZ2jI9PMSzMIVJ0Js/edit
>
>
> Thanks,
> Shreelekhya
>
>
>
> --
> Sent from:
> http://apache-carbondata-dev-mailing-list-archive.1130556.n5.nabble.com/
>

[Indhumathi]

+1. Please update design, for Map type having more than one level of complex
types.
For example, map<key, struct&lt;a:int, b:struct&lt;c:int, d:int>>


Regards,
Indhumathi M






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[VenuReddy]

+1

Nice idea. It improves the readibility.

Regards,
Venu



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[akashrn5]

Hi,

+1 for the new functionality.

my suggestion is to modify the DDL something like below

DESCRIBE column fieldname ON [db_name.]table_name;
DESCRIBE table short/transient [db_name.]table_name;

Others can give their suggestions

Thanks,

Regards,
Akash R



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[Ajantha Bhat]

Hi,

+1 for this improvement.

a) you can also print one line of short information about the parent column
when describe column is executed
to avoid executing again to know what is parent column type.
Example,
 Describe column decimalcolumn on complexcarbontable;
*You can mention that decimalcolumn is a MAP<> type and children are as
follows.*

b) Are you blocking describe column on primitive type ? or just print short
information about the primitive data type.
I think the latter one is fine.

Thanks,
Ajantha


On Mon, Mar 22, 2021 at 9:37 PM akashrn5 <[hidden email]> wrote:

> Hi,
>
> +1 for the new functionality.
>
> my suggestion is to modify the DDL something like below
>
> DESCRIBE column fieldname ON [db_name.]table_name;
> DESCRIBE table short/transient [db_name.]table_name;
>
> Others can give their suggestions
>
> Thanks,
>
> Regards,
> Akash R
>
>
>
> --
> Sent from:
> http://apache-carbondata-dev-mailing-list-archive.1130556.n5.nabble.com/
>

[maheshrajus]

Hi,

+1 for the feature.

Thanks & Regards
Mahesh Raju Somalaraju

On Thu, Mar 18, 2021 at 10:35 PM Shreelekhya <[hidden email]>
wrote:

> Hi,
>
> Currently describe formatted displays the column information of a table and
> some additional information. When complex types such as  ARRAY, STRUCT, and
> MAP types are present in table, column definition can be long and it’s
> difficult to read in a nested format.
>
> For complex types available, the DESCRIBE output can be formatted to avoid
> long lines for multiple fields. We can pass the complex field name to the
> command and visualize its structure as if were a table.
>
> DDL Commands:
> DESCRIBE fieldname ON [db_name.]table_name;
> DESCRIBE short [db_name.]table_name;
>
> Please let me know your valid inputs about the same.
> Following is the link to the design document.
>
>
> https://docs.google.com/document/d/1uNCByKR09Up9S2hpiEXYDA8XXIEZ2jI9PMSzMIVJ0Js/edit
>
>
> Thanks,
> Shreelekhya
>
>
>
> --
> Sent from:
> http://apache-carbondata-dev-mailing-list-archive.1130556.n5.nabble.com/
>

[vikramahuja1001]

+1 for this feature

Vikram Ahuja