table provides information about table constraint attributes
defined for primary and secondary storage engines.
table is reserved for future use.
table has these columns:
The name of the catalog to which the table belongs.
The name of the schema (database) to which the table belongs.
The name of the constraint.
The name of the table.
Constraint attributes defined for the primary storage engine. Reserved for future use.
Constraint attributes defined for the secondary storage engine. Reserved for future use.