Represents flags for RDB$CONSTRAINT_RELATIONS system table.

    Bit
    Position   Description

    0          Reserved for future use.
    1          Reserved for future use.
    2          If the constraint is on the specified table.
    3          If the constraint evaluates with optimization by dbkey
               lookup.
    4          If the constraint checks for existence.
    5          If the constraint checks for uniqueness.
    6          If the constraint needs to evaluate on store of
               specified table row.
    7          If the constraint need not evaluate on store of
               specified table row.
    8          If the constraint needs to evaluate on erase of
               specified table row.
    9          If the constraint need not evaluate on erase of
               specified table row.