This query lets you find out most popular column names.
Query
select c.column_name,
       count(*) as tables,
       round(100.0*count(*)::decimal
             /(select count(*)as tables
              from information_schema.tables
              where table_type = 'BASE TABLE'
              and table_schema not in ('information_schema', 'pg_catalog'))
       , 2) as percent_tables
from information_schema.columns c
join information_schema.tables t
     on t.table_schema = c.table_schema
     and t.table_name = c.table_name
where t.table_type = 'BASE TABLE' 
      and t.table_schema not in ('information_schema', 'pg_catalog')
group by c.column_name
having count(*) > 1
order by count(*) desc;
Columns
- column_name - column name
- tables - number of tables that have particular column name
- percent_tables - percentage of tables with column with that name
Rows
- One row represents particular column name (each name appears only once)
- Scope of rows: all colum names that appear at least twice (in two tables)
- Ordered by the most popular first
Sample results
Below is a list of most popular column names in pagila database. As you can see last_update column exists in 18 tables.

 
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                 
                                                             
                                                             
                                                             
                                                             
                                                                 
                                                             
                                                             
                                                                 
                                                             
                                                             
                                                             
                                                             Bart Gawrych
                                                                        Bart Gawrych
                                 PostgreSQL
                                                                PostgreSQL
                                 SQL Server
                                                                                                SQL Server
                                             Azure SQL Database
                                                                                                Azure SQL Database
                                             Oracle database
                                                                                                Oracle database
                                             Snowflake
                                                                                                Snowflake
                                             Amazon Redshift
                                                                                                Amazon Redshift
                                             IBM Db2
                                                                                                IBM Db2
                                             Vertica
                                                                                                Vertica
                                             MySQL
                                                                                                MySQL
                                             MariaDB
                                                                                                MariaDB