PGCES-02 Online Practice Questions and Answers

The tables "t1" and "t2" are defined below. The tables "t1" and "t2" have columns "id" which are type of INTEGER and column "name"s which are type of TEXT. t1 t2 The following SQL command was executed. Select the number of rows in the result. SELECT

*

FROM t1 NATURAL FULL OUTER JOIN t2;

A.

2 rows

B.

3 rows

C.

4 rows

D.

5 rows

E.

6 rows

Select two correct statements about the command shown below. Note: $ is the command prompt. $ dropdb -U foo foodb

A. If foo doesn't have the OS superuser privilege, an error will occur.

B. If any table definition remains in database foodb, an error will occur.

C. This command removes database foodb.

D. This command removes all of the objects inside the database foodb.

E. The same process can be performed using the SQL command "DROP DATABASE".

Based on the following request, select the most appropriate command for creating a database cluster.

?Character encoding of the template database needs to be EUC_JP ?Locale is not used A. initdb --locale=EUC_JP --no-encoding

B. initdb --default-encoding=EUC_JP

C. pg_ctl init --locale=EUC_JP

D. initdb --encoding=EUC_JP --no-locale

E. pg_ctl init --encoding=EUC_JP

The "sample" table consists of the following data. How many rows are returned by executing the following SQL statement?

SELECT i FROM sample GROUP BY i;

A. 1 row

B. 2 rows

C. 3 rows

D. 4 rows

E. 5 rows

Given the following two table definitions, select one SQL statement which will cause an error.

CREATE TABLE sample1 (id INTEGER, data TEXT);

CREATE TABLE sample2 (id INTEGER);

A. SELECT s1.id FROM sample1 s1;

B. SELECT s1.id FROM sample1 AS s1;

C. SELECT data FROM sample1 AS s1, sample2 AS s2 WHERE s1.id = 1 AND s2.id = 2;

D. SELECT id, data FROM sample1 AS s1, sample2 AS s2 WHERE s1.id = s2.id;

E. SELECT s1.id, s1.data FROM sample1 AS s1, sample2 AS s2 WHERE s1.id = s2.id;

The table "t1" is defined by the following SQL statement: CREATE TABLE t1 (id integer, name varchar

(20));

You want to increase the execution speed of the SQL statement below:

SELECT id, name FROM t1 WHERE id < 123 AND upper(name) = 'MAMMOTH'; Select the most suitable

SQL statement to create an index.

A. CREATE INDEX t1_idx ON t1 (id, upper(name));

B. CREATE INDEX t1_idx ON t1 USING HASH (id);

C. CREATE INDEX t1_idx ON t1 (name);

D. ALTER TABLE ADD INDEX ON t1 (id, upper(name));

E. ALTER TABLE ADD INDEX ON t1 (id, name);

Select one incorrect statement concerning changes from PostgreSQL version 7.4 to 8.0.

A. SAVEPOINT function was added.

B. Point-In-Time Recovery function was added.

C. The shared buffer control algorithm was improved.

D. Two-phase commit function was added.

E. CSV mode was added to the copy command.

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.