Summary of default values in Vertica database

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

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