PostgreSQL-CE PGCES-02 Exam Questions & Answers

Select two correct descriptions about views.

A. A view is created by 'DECLARE VIEW', and deleted by 'DROP VIEW'.

B. A view is a virtual table which does not exist.

C. A view is created to simplify complicated queries.

D. You can create a view with the same name as already existing tables.

E. A view only exists while the postmaster is running, and is deleted when the postmaster stops.

The following are statements related to the postmaster. Select one statement that is incorrect.

A. postmaster is a server process that receives connections from clients.

B. The "pg_ctl start" command boots up postmaster.

C. It is not possible to boot up the postmaster process by directly executing the postmaster command.

D. One postmaster process controls one database cluster.

E. The "pg_ctl stop" command stops postmaster.

SQL statements were executed in the following order.

CREATE TABLE book (

id VARCHAR(21), title TEXT NOT NULL, price INT,

UNIQUE (id), CHECK (price > 0)

);

INSERT INTO book VALUES ('4-12345-678-9', 'SQL book', 2300); --(1) INSERT INTO book (title, price)

VALUES ('PostgreSQL', 3000); --(2) UPDATE book SET id = '4-12345-678-9' WHERE id IS NULL; --(3)

DELETE FROM book WHERE price < 0; --(4)

While executing, select the first location that generates an error.

A. (1)

B. (2)

C. (3)

D. (4)

E. No error is generated.