Query returns basic statistics of numbers of columns in a database.
Query
select columns,
    tables,
    cast(1.0 * columns / tables as decimal (14,2)) as average_column_count
from 
(select count(*) as columns,
        count(distinct tab.tabname concat '.' concat tab.tabschema) as tables
    from syscat.tables tab
    inner join syscat.columns col 
        on col.tabschema = tab.tabschema
        and col.tabname = tab.tabname
    where tab.type = 'T'
        and tab.tabschema not like 'SYS%'
) q
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

 
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                 
                                                             
                                                             
                                                             
                                                             
                                                                 
                                                             
                                                             
                                                                 
                                                             
                                                             
                                                             
                                                             Marcin Nagly
                                                                        Marcin Nagly
                                 IBM Db2
                                                                IBM Db2
                                 SQL Server
                                                                                                SQL Server
                                             Azure SQL Database
                                                                                                Azure SQL Database
                                             Oracle database
                                                                                                Oracle database
                                             Snowflake
                                                                                                Snowflake
                                             Amazon Redshift
                                                                                                Amazon Redshift
                                             Teradata
                                                                                                Teradata
                                             Vertica
                                                                                                Vertica
                                             PostgreSQL
                                                                                                PostgreSQL
                                             MySQL
                                                                                                MySQL
                                             MariaDB
                                                                                                MariaDB