Independent of all physical considerations

Tailored to a specific DBMS

A description of the database implementation on secondary storage

Based on a specific data model, such as the relational model

Database planning

Operational maintenance

DBMS selection

Normalization

Vertical prototyping

Requirements prototyping

Evolutionary prototyping

Operational prototyping

RESTRICT rejects the drop if other objects depend on the table; CASCADE drops the table together with all dependent objects.

CASCADE rejects the drop if other objects depend on the table; RESTRICT drops them too.

RESTRICT drops the table and its rows; CASCADE only drops the rows.

RESTRICT works only on views; CASCADE works only on base tables.

There is no difference — the two declarations are interchangeable.

VARCHAR(30) always occupies 30 characters, exactly like CHAR(4) occupies 4.

CHAR is for numeric codes and VARCHAR is for text; they cannot be compared.

CHAR(4) always occupies 4 characters; VARCHAR(30) uses only as many characters as needed, up to a maximum of 30.

STOP WHEN x > 5;

LEAVE LOOP;

EXIT WHEN x > 5;

BREAK;

A view selecting a subset of columns from a single base table.

A view that renames the columns of a single base table.

A view defined with GROUP BY and COUNT(*) (like StaffPropCnt).

A view filtering the rows of one table with a WHERE clause.

To save the changes made by a transaction

To undo the changes made by a transaction

To commit the changes made by a transaction

To finalize the changes made by a transaction

GRANT UPDATE

GRANT UPDATE (salary)

GRANT SELECT (salary)

GRANT UPDATE

RETURNS TRIGGER — for example CREATE OR REPLACE FUNCTION check_advisor_load() RETURNS TRIGGER ...

RETURNS VOID — trigger functions return nothing.

No RETURNS clause — CREATE TRIGGER holds the body directly.

RETURNS TABLE — trigger functions return the affected rows.