siganakis

    (!R)@&{&/x!/:2_!x}'!R

    (~R∊R∘.×R)/R←1↓ιR

    SELECT 
        COUNT(*) as columns,
        column_type,
        table_name
    FROM (
        SELECT  c.id, 
                c.type AS column_type,
                t.name AS table_name
        FROM tables t
        INNER JOIN columns c
        ON t.id = c.table_id
        WHERE t.system=false;
    ) a
    HAVING COUNT(*) > 1
    ORDER BY columns DESC

    # Use ":="  to replace WITH for named ephermal views
    # Replace "WHERE" with "?", "SELECT" with "|>" at the end
    non_system := tables 
        ? system=false 
        |> name:table_name, is:table_id

    # Replace INNER JOIN with "*="
    non_system_columns := non_system.table_id *= columns.table_id
        |> c.id, c.type:column_type

    # GROUP BY columns are automatically generated by non-aggregated columns
    column_types := non_system_columns
        |> COUNT(*):columns DESC, column_type, table_name

    non_system := tables ? system=false 
        |> name:table_name, is:table_id
    non_system_columns := non_system.table_id *= columns.table_id
        |> c.id, c.type:column_type
    
    non_system_columns 
        |> COUNT(*):columns DESC, column_type, table_name