| 1. Which size distinction between VARRAYs and nested tables is correct in Oracle 26ai? Select the one best answer. | |
| Correct answer | |
No valid answer selected. The VARRAY limit is capacity, not current population: an initialized VARRAY can contain fewer elements, including zero. A nested-table type has no declared maximum count. Both schema-level collection kinds can be persisted and queried with SQL. Oracle 26ai reference. | |
| 2. An object table persons has an embedded addr object with a city attribute. With table alias p, which query selects that scalar city? Select the one best answer. | |
| Correct answer | |
No valid answer selected. The aliased path p.addr.city follows the embedded address attribute to its scalar city. p.city would require a top-level city attribute. REF(p) returns a row-object reference, while VALUE(p) returns the whole person value. Neither is the requested scalar projection. Oracle 26ai reference. | |
| 3. Which statement about PL/SQL collection indexes is correct in Oracle 26ai? Select the one best answer. | |
| Correct answer | |
No valid answer selected. VARRAYs and nested tables use integer indexes in PL/SQL. Associative arrays can use PLS_INTEGER or string keys. A string key is not an enumeration declaration. Persisted nested tables do not preserve a durable element order or identity from their procedural indexes; store a business key or sequence attribute when needed. Oracle 26ai reference. | |
| 4. Which query returns each complete person object instance from the object table persons, using table alias p? Select the one best answer. | |
| Correct answer | |
No valid answer selected. VALUE(p) returns the object instance represented by each row of the object table. REF(p) returns a reference to that row object, the attribute path selects only a scalar city, and COUNT(*) returns a row count. Oracle 26ai reference. | |
| 5. Which statement about a REF column constrained with SCOPE IS persons is correct in Oracle 26ai? Select the one best answer. | |
| Correct answer | |
No valid answer selected. SCOPE restricts REF values to row objects of the specified object table. It does not provide the existence guarantee of a referential integrity constraint; scoped references can be dangling when their target rows no longer exist. A REF identifies a row object rather than storing a copy of it. Oracle 26ai reference. | |