Обсуждение: Unable to query information_schema.constraint_column_usage

Hello, all.

I’m trying to build a query that joins several information_schema views. The role I’m using has SELECT and USAGE permissions into the account whose tables I care about.

I connect as the role and run this:

select count(*) from information_schema.table_constraints;

count

-------

  1125

(1 row)

All good.

Now I run this:

select count(*) from information_schema.constraint_column_usage;

count

-------

     0

(1 row)

This view is missing data on several foreign key constraints that exist in the schema I care about. When I run these queries as ‘postgres’, they work fine (naturally).

What permissions do I need to grant the querying role so it can see the constraint columns belonging to another schema? Why does querying on the table_constraints view work, but on constraint_column_usage not work?