The syscoldepend system catalog table tracks the table columns specified in check constraints and in NOT NULL constraints. Because a check constraint can involve more than one column in a table, the syscoldepend table can contain multiple rows for each check constraint; one row is created for each column involved in the constraint. The syscoldepend table has the following columns.
Column Type Explanation
constrid INTEGER Code uniquely identifying the constraint
tabid INTEGER Code uniquely identifying the table
colno SMALLINT Column number within the table

A composite index on the constrid, tabid, and colno columns allows only unique values. A composite index on the tabid and colno columns allows duplicate values.

See also the syscheckudrdep system catalog table in SYSCHECKUDRDEP, which lists every check constraint that is referenced by a user-defined routine.

See also the sysreferences table in SYSREFERENCES, which describes dependencies of referential constraints.