Viewing constraint definitions for a table
Constraint definitions on a table can be found in the SYSCAT.INDEXES and SYSCAT.REFERENCES catalog views.
About this task
The UNIQUERULE column of the SYSCAT.INDEXES view indicates the characteristic of the index. If the value of this column is P, the index is a primary key, and if it is U, the index is a unique index (but not a primary key).
The SYSCAT.REFERENCES catalog view contains referential integrity (foreign key) constraint information.