Question No. 1

Select two suitable statements regarding the following SQL statement:

CREATE TRIGGER trigger_1 AFTER UPDATE ON sales FOR EACH ROW EXECUTE PROCEDURE write_log();

AIt is defining a trigger 'trigger_1'.

BEvery time 'UPDATE' is executed on the 'sales' table, the 'write_log' function is called once.

CThe 'write_log' function is called before 'UPDATE' takes place.

D'UPDATE' is not executed if 'write_log' returns NULL.

E'DROP TRIGGER trigger_1 ON sales;' deletes the defined trigger.

Show Answer

Correct Answer: A, E

Question No. 2

Select two transaction isolation levels supported in PostgreSQL.

ADIRTY READ

BREAD COMMITTED

CREPEATABLE READ

DPHANTOM READ

ESERIALIZABLE

Show Answer

Correct Answer: B, E

Question No. 3

PostgreSQL can use an index to access a table. Select two incorrect statements about indexes.

AAn index is created by 'CREATE INDEX', and deleted by 'DROP INDEX'.

BBy using an index effectively, searching and sorting performs faster.

CThere are B-tree, Hash, R-tree and GiST index types.

DBy creating an index, performance always improves.

ECreating an unused index does not affect the performance of a database at all.

Show Answer

Correct Answer: D, E

Question No. 4

Select two incorrect statements regarding 'DOMAIN'.

AWhen defining a domain, you can add a default value and constraints to the original data.

BDomain is a namespace existing between databases and objects such as tables.

CA domain is created by 'CREATE DOMAIN'.

DA domain can be used as a column type when defining a table.

ETo define a domain, both input and output functions are required.

Show Answer

Correct Answer: B, E

Question No. 5

Select two suitable statements regarding the data types of PostgreSQL.

AOne field can handle up to 1GB of data.

B'n' in CHARACTER(n) represents the number of bytes.

COnly the INTEGER type can be declared as an array.

DThere is a non-standard PostgreSQL data type, called Geometric data type, which handles 2dimensional data.

EA large object data type can be used to store data of unlimited size.

Show Answer

Correct Answer: A, D

Free PostgreSQL PGCES-02 Exam Actual Questions