PostgreSQL-CE PGCES-02 Online Practice Questions and Exam Preparation

PostgreSQL-CE PGCES-02 Online Questions & Answers

• Question 121:

  Based on the relationship of columns within a table, select the most suitable description that shows that column A is dependent on column B.

  A. The value in column B is uniquely determined when a value in column A is selected.
  B. The value in column A is uniquely determined when a value in column B is selected.
  C. When the value in column A is changed, the corresponding value in column B also must be changed.
  D. When the value in column B is changed, the corresponding value of column A also must be changed.
  E. As long as column B exists, the amount of information will not decrease even if column A is deleted.
  B. The value in column A is uniquely determined when a value in column B is selected.

• Question 122:

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

  A. An index is created by 'CREATE INDEX', and deleted by 'DROP INDEX'.
  B. By using an index effectively, searching and sorting performs faster.
  C. There are B-tree, Hash, R-tree and GiST index types.
  D. By creating an index, performance always improves.
  E. Creating an unused index does not affect the performance of a database at all.
  D. By creating an index, performance always improves.
  E. Creating an unused index does not affect the performance of a database at all.

• Question 123:

  A table and view are defined as follows:

  CREATE TABLE item (id INT, name TEXT, description TEXT); CREATE VIEW item_simple AS SELECT id, name FROM item;

  A set of SQL statements were executed in the order below. Select the most appropriate statement concerning the execution results.

  BEGIN;

  SELECT * FROM item_simple;

  INSERT INTO item_simple VALUES (1, 'item_name_1'); UPDATE item_simple SET name = 'item_name_2' WHERE id = 1; DELETE FROM item_simple;

  END;

  A. An error is generated at the point the SELECT statement is executed.
  B. An error is generated at the point the INSERT statement is executed.
  C. An error is generated at the point the UPDATE statement is executed.
  D. An error is generated at the point the DELETE statement is executed.
  E. No error is generated.
  B. An error is generated at the point the INSERT statement is executed.

• Question 124:

  Select one false statement about the benefits of using database management systems from below.

  A. You can separate the data storage method from the application.
  B. You can separate the data search method from the application.
  C. You can separate the data display method from the application.
  D. You can reduce the programming workload of programming for managing data.
  E. You can share data more easily on systems consisting of multiple computers.
  C. You can separate the data display method from the application.

• Question 125:

  Select one correct statement about the createlang command.

  A. It is a command for setting the locale for a database.
  B. It is a command for registering a procedural language into a database.
  C. It is a command for creating a user defined function.
  D. It is a command for adding message catalogs.
  E. It is a command that has been discarded for version 8 and later.
  B. It is a command for registering a procedural language into a database.

• Question 126:

  What phenomenon occurs if PostgreSQL is used without performing VACUUM ? Select two appropriate descriptions from those below.

  A. Performance is reduced.
  B. It gradually gets to the point where connections are denied.
  C. The physical size of the database increases considerably in size.
  D. Only SELECT queries will be accepted.
  E. An e-mail prompting the administrator to perform VACUUM is sent from PostgreSQL.
  A. Performance is reduced.
  C. The physical size of the database increases considerably in size.

• Question 127:

  The tables "s1" and "s2" are defined below. The column "id" for tables "s1" and "s2" is of INTEGER type. The column "enable" for table "s1" is of BOOLEAN type, and the column "name" for table "s2" is of TEXT type. s1: id | enable ----+-------1 | t 2 | f s2: id | name ----+-----1 | post 2 | gre 3 | SQL The following SQL was executed. Select the correct number of rows in the result. SELECT * FROM s2 WHERE id IN (SELECT id FROM s1);

  A. 1 row
  B. 2 rows
  C. 3 rows
  D. 4 rows
  E. 5 rows
  B. 2 rows

• Question 128:

  SQL statements were executed in the following order: CREATE TABLE fmaster (id INTEGER PRIMARY KEY, name TEXT); CREATE TABLE ftrans (id INTEGER REFERENCES fmaster (id), stat INTEGER, date DATE); INSERT INTO

  fmaster VALUES (1, 'itemA');

  INSERT INTO ftrans VALUES (1, 1, CURRENT_DATE);

  Select two SQL statements that will generate an error when executed next.

  A. INSERT INTO ftrans VALUES (1, 1, CURRENT_DATE);
  B. INSERT INTO ftrans VALUES (2, 1, '2007-07-07');
  C. UPDATE fmaster SET name = 'itemAX' WHERE id = 1;
  D. UPDATE fmaster SET id = 100 WHERE id = 1;
  E. UPDATE ftrans SET id = 200 WHERE id = 1;
  A. INSERT INTO ftrans VALUES (1, 1, CURRENT_DATE);
  C. UPDATE fmaster SET name = 'itemAX' WHERE id = 1;

• Question 129:

  I would like to set the default character encoding for the client to Unicode. Select the most appropriate configuration parameter in postgresql.conf from those below.

  A. backend_encoding = UNICODE
  B. frontend_encoding = UNICODE
  C. client_encoding = UNICODE
  D. default_encoding = UTF8
  E. encoding = UTF8
  C. client_encoding = UNICODE

• Question 130:

  The table "custom" is defined below. The "id" column and "introducer" column are of INTEGER type, and the "email" column is of TEXT type. id | email | introducer ----+-----------------+-----------2 | [email protected] | 1 3 | [email protected] | 2 4 | [email protected] | 2 Three SQL statements were executed in the following order: UPDATE custom SET email = '' FROM custom c WHERE custom.introducer = c.id; UPDATE custom SET introducer = NULL WHERE introducer NOT IN (SELECT id FROM custom); DELETE FROM custom WHERE id = 2 OR introducer = 2; Select the number of rows in the "custom" table after the execution.

  A. 0 rows
  B. 1 row
  C. 2 rows
  D. 3 rows
  E. 4 rows
  A. 0 rows