SYSCOLDEPEND
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.