If a table has a constraint but no index, can I assume that the only difference is that I am leaving it to Oracle to determine how determine whether changes to the table violate the constraint, perhaps resulting in Oracle having to do table scans to determine it?

```
CREATE TABLE SchemaName."Table1" (
  field_one VARCHAR2(10 BYTE) NOT NULL,
  field_two VARCHAR2(30 BYTE) NOT NULL,
  field_three DATE NOT NULL,
  (etc)
  CONSTRAINT client_iu1 UNIQUE (field_one,field_two,field_three)
);

```

vs.

```
CREATE TABLE SchemaName."Table1" (
  field_one VARCHAR2(10 BYTE) NOT NULL,
  field_two VARCHAR2(30 BYTE) NOT NULL,
  field_three DATE NOT NULL,
  (etc)
   CONSTRAINT client_ak1 UNIQUE (field_one,field_two,field_three) USING INDEX fds_base.client_iu1
);

```