DM3.0 EA2: Logical Model Relation Cardinality:Source Optional mislabeled?

Question

In logical model, created a 1:N non-identifying relation between 2 entities - Parent and Child. Parent is 1:N with Child. Both entities have a single column primary key - parent_id and child_id respectively. I would like to enforce RI such that a parent may exist with no children, but a child may not exist without a parent.
In the logical model the relation properties, cardinality - I modify the Source Optional and Target Optional checkboxes to achieve my desired result. I first tried checking Target Optional and leaving Source Optional un-checked. I then engineer a physical model and generate DDL for Oracle 11g I get this constraint:
SQL>ALTER TABLE child
  2      ADD CONSTRAINT Relation_1 FOREIGN KEY
  3      (
  4       parent_id
  5      )
  6      REFERENCES parent
  7      (
  8       parent_id
  9      )
10      ON DELETE SET NULL
11  ;
Table altered.Here's a test case illustrating this isn't quite what I wanted (starting with both tables empty):
SQL>
SQL>
SQL>insert into parent (parent_id) values (1);
1 row created.
SQL>commit;
Commit complete.
SQL>
SQL>insert into child (child_id, parent_id) values (901, 1);
1 row created.
SQL>commit;
Commit complete.
SQL>
SQL>delete from parent;
delete from parent
ERROR at line 1:
ORA-01407: cannot update ("ODS_ETL_OWNER"."CHILD"."PARENT_ID") to NULLIf I have Source Optional checked, and Target Optional not checked, engineer a physical model and generate DDL for Oracle 11g I get this constraint which produces the desired results with my test case:
SQL>ALTER TABLE child
  2      ADD CONSTRAINT Relation_1 FOREIGN KEY
  3      (
  4       parent_id
  5      )
  6      REFERENCES parent
  7      (
  8       parent_id
  9      )
10  ;
Table altered.
SQL>
SQL>insert into parent (parent_id) values (1);
1 row created.
SQL>commit;
Commit complete.
SQL>
SQL>insert into child (child_id, parent_id) values (901, 1);
1 row created.
SQL>commit;
Commit complete.
SQL>
SQL>delete from parent;
delete from parent
ERROR at line 1:
ORA-02292: integrity constraint (ODS_ETL_OWNER.RELATION_1) violated - child
record foundBut that seems backwards - and the documentation also reads as if it’s backwards. Am I missing something or are the Source Optional and Target Optional checkboxes mislabeled? Should they be Source Manditory and Target Manditory?

Answer 1

I would like to enforce RI such that a parent may exist with no children, but a child may not exist without a parent.You need to set parent as optional and child to be mandatory.
Am I missing something or are the Source Optional and Target Optional checkboxes mislabeled? Should they be Source Manditory and Target Manditory?There is a relationship and two ends of that relationship and you can set for each end whether it's optional or not. And that's seen directly using Barker notations. Source and target optionality place will be swapped on diagram if you use IE notation.
I expected that cardinality part could be more confusing for you because at source end you define cardinality of the target, but it seems you have no problem with that.
Philip