The lesson emphasizes testing an UPDATE using a SELECT first. Why?
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Why must database design follow the conceptual → logical â…
Why must database design follow the conceptual → logical → physical sequence rather than beginning with implementation choices?
What does X -> Y represent?
What does X -> Y represent?
In which situation is it most appropriate for a designer to…
In which situation is it most appropriate for a designer to generate a surrogate key rather than rely on an existing attribute?
Which artifact most clearly expresses who does what and why,…
Which artifact most clearly expresses who does what and why, suitable for validating business goals with stakeholders?
Which outcome follows from this sequence?UPDATE t SET x = x…
Which outcome follows from this sequence?UPDATE t SET x = x + 1 WHERE id = 5;SAVEPOINT p1;UPDATE t SET x = x + 1 WHERE id = 5;ROLLBACK TO p1;COMMIT;
Which pattern best describes pessimistic concurrency control…
Which pattern best describes pessimistic concurrency control?
What is the effect of COUNT(column_name) compared to COUNT(*…
What is the effect of COUNT(column_name) compared to COUNT(*)?
Which query correctly returns the current database date/time…
Which query correctly returns the current database date/time as demonstrated by Oracle examples?
Why is relying on the application layer to detect duplicates…
Why is relying on the application layer to detect duplicates risky when inserting new records under concurrency?