Query below summarizes default constraints in a database listing all distinct default value definitions for columns with the number of their occurrence.

Query

select column_default,
       count(distinct table_id) as tables,
       count(column_name) as columns
from v_catalog.columns
group by column_default
order by count(column_name) desc;

Columns

• column_default - definition of default constraint (formula)
  • [NULL] for identity columns
  • blank column default means default constaint was not defined
• tables - number of tables with this constraint (or number of tables with columns with no constraints for blank row)
• columns - number of columns with this particular constraint (or no constraint for blank row)

Rows

• One row represents one unique definition of default value
• Scope of rows: all distinct definitions of default column values in a database
• Ordered by the number of occurrences from the most popular

Sample results