Table "t1" is defined as follows:

CREATE TABLE t1 (value VARCHAR(5));

A set of SQL statements were executed in the following order. Select the number of rows that table "t1"

has after execution.

BEGIN;

INSERT INTO t1 VALUES ('AA'); SAVEPOINT point1;

INSERT INTO t1 VALUES ('BB'); SAVEPOINT point2;

INSERT INTO t1 VALUES ('CC'); ROLLBACK TO point1;

INSERT INTO t1 VALUES ('DD'); END;

A. 1 row

B. 2 rows

C. 3 rows

D. 4 rows

E. 0 rows

Select one incorrect description regarding the following SQL statement defining a function. CREATE OR REPLACE FUNCTION get_file_list(TEXT, BOOLEAN) RETURNS SETOF TEXT LANGUAGE C STRICT SECURITY DEFINER AS 'myfuncs.so';

A. This function may be defined in 'myfuncs.so'.

B. This function can return multiple rows.

C. This SQL statement defines a function written in the C language.

D. If this function is called with a NULL parameter, it will return 0 when executed.

E. This function operates with the authority of the user who executed it.

Select two appropriate statements from below about the following SQL statements: CREATE FUNCTION myfunc(INTEGER) RETURNS text LANGUAGE plpgsql STRICT AS ' DECLARE x ALIAS FOR $1; r text := ''default''; BEGIN IF x > 100 THEN SELECT INTO r data FROM mytable WHERE id = x; END IF; RETURN r; END;';

A. An error is generated unless the plpgsql language is registered in the database beforehand.

B. The execution results of SELECT myfunc(-123) differs based on the content of "mytable".

C. When SELECT myfunc(123) is executed an error occurs.

D. When SELECT myfunc(NULL) is executed an error occurs.

E. When SELECT myfunc (0) is executed the text "default" is returned.

Which psql command do you need to execute to display the list of tables in the currently connected database?

A. SELECT * FROM pg_table_list;

B. SHOW tables;

C. \dT

D. \dt "database_name"

E. \dt

Select two suitable statements about postgresql.conf configuration.

A. A line that starts with ! (exclamation mark) is interpreted as a comment.

B. You can have different parameters for the same option to configure each database differently.

C. The timing of when a change in any value is reflected is different depending on the configuration parameter.

D. All options have no default values. Therefore, all of them must be set specifically and thoroughly.

E. As a boolean value, any of the following can be used: TRUE, FALSE, ON, OFF, YES, NO, 0.1