Query that returns tables with number of columns, ordered from the ones that have the most.
Query
select 
    tabschema concat '.' concat tabname as table_name, 
    colcount as columns
from syscat.tables
where type = 'T'
order by colcount desc
Columns
- table - name of the table (with schema name)
- columns - number of columns in table
Rows
- One row represents one table in a database
- Ordered by number of columns descending - from tables with the most columns
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
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                                             MariaDB
                                                                                                MariaDB