Oracle Oracle Certifications 1Z0-874 Questions & Answers

• Question 41:

  Which of the following best describes why one should use VARCHAR rather than CHAR in InnoDB?

  A. The average amount of space used will be less.

  B. Generally, there will be less disk I/O during processing.

  C. VARCHAR columns provide better transaction support.

  D. The optimizer always performs better with VARCHAR columns over CHAR columns.

  Correct Answer: B

• Question 42:

  Doing SELECT COUNT(*) queries in InnoDB is efficient...

  A. Yes, because InnoDB stores a row count in the table.

  B. No, because InnoDB does not store a row count in the table.

  C. Yes, if the table has any indexes.

  D. No, because the table must be sorted.

  Correct Answer: B

• Question 43:

  Why should one preferably group multiple statements for InnoDB tables within a transaction whenever it is possible?

  A. It minimizes bandwidth usage.

  B. It helps keep log file sizes down.

  C. It minimizes the amount of flush operations needed.

  D. It helps reduce the chance of the transaction failing due to a bad query.

  Correct Answer: C

• Question 44:

  Which of the following would be considered a good candidate table for compression?

  A. A table with data that needs only few updates in the future.

  B. A table with data that will not be updated in the future.

  C. A large table, such as those used for data warehousing.

  D. All MyISAM tables are good candidates for compression.

  Correct Answer: B

• Question 45:

  Which of the following statements are true of compressed tables?

  A. They can be uncompressed.

  B. They can not be uncompressed.

  C. They can be uncompressed but some data corruption may occur.

  Correct Answer: A

• Question 46:

  Which of the following best describes when it might be advantageous to split a dynamic-row table into dynamic-row and fixed-row tables?

  A. When the table contains both fixed and variable length columns, but the majority of queries on it access the fixed length columns.

  B. When the table contains both fixed and variable length columns, but the majority of queries on it access the variable length columns.

  C. When the table contains both fixed and variable length columns, and the majority of queries access both the variable and fixed length columns.

  Correct Answer: A

• Question 47:

  Can multi-column FULLTEXT indexes be used? If so, when?

  A. No, they can not be used.

  B. Yes, they should be used to search multiple columns simultaneously.

  C. Yes, they can be used to search either one or all of the indexed columns.

  Correct Answer: B

• Question 48:

  Consider the following:

  +----+-----------------+--------------+

  | id | PartName | Location |

  +----+-----------------+--------------+

  | 1 | 40GB Hard Drive | Jacksonville |

  | 2 | 1GB DDR | Atlanta |

  | 3 | Keyboard | San Jose |

  | 4 | Monitor | Harrisburg |

  | 5 | USB Drive | Miami |

  | 6 | DVD/R | Jacksonville |

  +----+-----------------+--------------+

  Which of the following best describes why this table should be split into a part and location table?

  A. Because it has redundant location values.

  B. Because it has multiple repeating groups in each row.

  C. This table should not be split as it is already in third normal form.

  Correct Answer: A

• Question 49:

  What benefits do you get after compressing a MyISAM table?

  A. The files on disk consume less space.

  B. Retrieving rows usually becomes faster.

  C. The index information will be kept fully in memory, which results in faster performance when using WHERE clauses.

  D. Using COUNT(*) is faster since the number of rows is constant.

  Correct Answer: D

• Question 50:

  Which of the following best describe the effects on performance for the dynamic-row format for MyISAM has?

  A. Retrievals are more complex and slower.

  B. Retrievals are less complex and are faster.

  C. Rows generally take up less disk space than fixed-row format.

  D. Rows generally take up more disk space than fixed-row format.

  Correct Answer: B