Thread: Accessing referential constraint information with minimal permissions
Hello,
I want to programmatically read all the references in a database. Ideally, I want to do it with read-only permissions to the table. Is it possible?
I know the information is in `information_schema.referential_constraints`, but apparently reading that information requires having write permissions to the tables that have references. I don't know why it's designed like that. I think knowing the relationships between tables is in the same class of privileges as knowing the columns in the tables. (which you can do by reading the `columns` view with just SELECT permissions)
Anyway, is there a workaround for this? If not, what is the least destructive write permission I can give a user who wants this access?
Cheers,
Avin.
Re: Accessing referential constraint information with minimal permissions
From
Christoph Moench-Tegeder
Date:
## Avin Kavish (avin@baseboard.ai): > I know the information is in `information_schema.referential_constraints`, > but apparently reading that information requires having write permissions > to the tables that have references. I don't know why it's designed like > that. I guess because "the standard says so". But then, information_schema.referential_constraints is only a view and the privilege check is coded into the view, so you could just take the query from the view and omit the privilege check and Bob is your uncle. Another way to approach your problem would be via pg_catalog.pg_constraint https://www.postgresql.org/docs/current/catalog-pg-constraint.html and maybe use pg_get_constraintdef() as documented in this table: https://www.postgresql.org/docs/current/functions-info.html#FUNCTIONS-INFO-CATALOG-TABLE Another way to learn about these internals is to use psql with argument -E (--echo-hidden, or "\set ECHO_HIDDEN on") and watch psql's queries when displaying objects. Regards, Christoph -- Spare Space