\ss without arguments lists columns for all tables

[nineinchnick]

\ss without arguments lists columns for all tables, including system catalogs. It would be more useful if it only listed the summary row for every table.

[kozikowskik]

Hi,
I just started to work on this issue, but I have a question. Does all metrics returned by \ss for a single column will make sense as cumulative data for a whole table? To be more specific. Currently usql shows:

- Average width
- Nulls fraction
- Distinct values
- Minimum value
- Maximum value
- Mean value
- Top N common values
- Top N values freqs

The metrics which I'm wandering if make sense in the whole table context are values-related metrics:

- Minimum value
- Maximum value
- Mean value
- Top N common values
- Top N values freqs

[nineinchnick]

\ss without arguments can be an alias to \dt+