Oracle Oracle Certifications 1Z0-882 Questions & Answers

• Question 71:

  Which two PHP modules provide APIs for developing MYSQL applications?

  A. Mysqli

  B. Mysqlnd

  C. PDO

  D. PDO_mysql

  Correct Answer: AC

• Question 72:

  Inspect the query:

  Mysql> SELECT count (emp_no) FROM titles WHERE title = `senior staff';

  

  How can this query be optimized?

  A. The query need an index on the emp-no column.

  B. The query cannot be optimized as an index is already used.

  C. The query needs an index that includes the title column.

  D. The query cannot be optimized as count () must read all rows.

  Correct Answer: B

• Question 73:

  Your MYSQL server was successfully running for a days, and then suddenly stopped .You are sure that no

  mysqld process is running.

  Which two may provide diagnostic information to help determine why the MYSQL server stopped?

  A. The general query log file

  B. The syslog on Linux/UNIX or the Event view on windows

  C. The slow query log file

  D. The MYSQL server error log file

  E. The binary log file

  Correct Answer: DE

• Question 74:

  Consider the table t1 created with this statement:

  CREATE TABLE t1(

  id INT NOT NULL AUTO_INCREMENT

  PRIMARY KEY,

  Name CHAR (20)

  ENGINE=InnoDB;

  After inserting three rows, the table contains:

  

  These commands are executed: DELETE FROM t1 WHERE id=200; INSERT INTO t1 (name) VALUES (`pluto'): Which data set is inserted in the table?

  A. (200.pluto)

  B. (101,Pluto)

  C. (201,Pluto)

  D. (300,Pluto)

  Correct Answer: A

• Question 75:

  A SELECT statement without an ORDER BY clause return some rows.

  Which statement is always true about the order of the returned results?

  A. The results are in ascending order.

  B. The results are in descending order.

  C. The results are in the order inserted.

  D. The results are not in a set order.

  Correct Answer: C

• Question 76:

  A complex query consists of eight populated tables that are all connected via INNER JOIN operands as shown:

  

  You modify the query and replace the SELECT operand with SELECT STRAIGHT JOIN. What is the effect of adding STRAIGHT JOINs to the query?

  A. The optimizer processes only the JOINs in the sequence listed in the query.

  B. The optimizer will only JOIN the tables by using their PRIMARY KEYS or UNIQUE constraints.

  C. The optimizer will only JOIN the tables in sequence from smallest to largest.

  D. The optimizer ignores all terms in the WHERE clause until all JOINs have been completed.

  Correct Answer: B

• Question 77:

  Which two can be used to obtain information stored in the Diagnostics Area?

  A. SHOW WARNINGS

  B. GET DIAGNOSTICS CONDITION 1 @errno=MYSQL_ERRNO, @msg =MESSAGE_TEXT; SELECT @errno, @msg;

  C. SELECT ERRNO, MESSAGE_TEXT FROM INFORMATION_SCHEMA.DIAGNOSTICS_AREA WHERE CONDITION=1

  D. SHOW GLOBAL STATUS LIKE `Diagnostics'

  Correct Answer: AB

• Question 78:

  Which there statements describe valid reasons why queries that use "SELECT" construct are discouraged?

  A. SELECT * may cause more data than you need to be read from disk if your application needs only some columns.

  B. SELECT * causes more data than you need to be sent via the client/server protocol if your application needs only some columns.

  C. SELECT * prevents the use of indexes, so a full table scan for every query.

  D. SELECT *causes your application to depend on the columns present when you wrote it , so your application could break if the table structure changes.

  E. SELECT * causes the statements to return all rows from the table.

  Correct Answer: DE

• Question 79:

  Which statement is true about the difference between HASH and BTREE INDEXES?

  A. HASH indexes support rightmost prefixing of keys, which makes them faster than BTREE indexes in many causes.

  B. HASH indexes can be used by the optimizer to speed up ORDER BY operations and not BTREE indexes.

  C. HASH indexes are used only for equality comparisons (= or<=>),whereas BTREE indexes can also be used for range searches (>or<).

  D. HASH indexes are much faster than BTREE indexes but can only be used for a single column.

  Correct Answer: C

• Question 80:

  Which two code samples demonstrate valid methods for working with loops?

  A. DECLARE I INT DEFAULT 0; Test_loop: LOOP SET i =i +1; IF i> =5 THEN LEAVE test_loop; END IF; END LOOP test_loop;

  B. DECLARE i INT DEFAULT 0; WHILE I < 5ITERATE SET i = i +1; END WHILE;

  C. DECLARE i INT DEFAULT 0; WHILE i < 5 Do SET i = i + 1; END WHILE;

  D. DECLARE i INT DEFAULT 0; Test _loop; LOOP SET i =i +1; IF i >=5 THEN LEAVE; END IF; END LOOP test_loop;

  Correct Answer: C