Query below returns the average number of columns per table in a database.

Query

select count(*) as columns,
       count(distinct t.table_schema || '.' || t.table_name) as tables,
       round ((count(*)::decimal
            / count(distinct t.table_schema || '.' || t.table_name)), 2)
        as average_column_count
from information_schema.tables t
left join information_schema.columns c on c.table_schema = t.table_schema
          and c.table_name = t.table_name
where t.table_schema not in ('information_schema', 'pg_catalog')
      and table_type = 'BASE TABLE';

Columns

• columns - total number of columns in a database
• tables - number of tables in a database
• average_column_count - average number of columns in a table in a database

Rows

• Query returns just one row

Sample results