Questão 534037

• Banca: ESAF
• Órgão: CVM
• Ano: 2010
• Provas: ESAF - 2010 - CVM - Analista de TIC - Infraestrutura - prova 2
• Disciplina: Banco de Dados
• Assuntos: SQL Server

No SQL Server 2005, transações de E/S incompletas, causadas por erros de E/S, podem ser verificadas por

• A. CHECKTRANSACTIONS. TORN_PAGE_ DESECTION. NONE.
• B. CHECKSUM. TORN_PAGE_SPLITTER. SOME.
• C. CHECKTRANSACTIONS.TURN_ERROR_ DETECTION. NONE.
• D. CHECKSUM.TORN_PAGE_DETECTION. NONE.
• E. BUBBLE_APPROACH. TURN_AND_GO. NEW.

Gabarito: D

Comentários

•  

  Propriedades do Banco de dados (página Opções)
  Página Verificar
  Especifique a opção usada para descobrir e relatar transações de E/S incompletas provocadas por erros de E/S em disco. Nenhum, TornPageDetection e Soma de Verificação.
  http://msdn.microsoft.com/pt-br/library/ms188124.aspx

• PAGE_VERIFY can take one of the three values:
  CHECKSUM, TORN_PAGE_DETECTION or NONE.
   
  The default and recommended value providing the most protection is CHECKSUM. This option advises SQL Server to calculate a checksum over the contents of each data / index page when it is written to disk. This value is stored in the page header. When the page is read from the disk, checksum is computed again and compared to the value in page header. 
  
  The TORN_PAGE_DETECTION value configures SQL Server to save a specific bit for each 512 byte sector on the data / index page. This allows SQL Server to detect I/O operations that might have been interrupted due to power failures or other types of system outages. If the saved bit is in a wrong state when the page is read from disk, the error 824 will be raised indicating a torn page. 
  
  The value of NONE advises SQL Server not to compute checksums nor flip bits for detecting torn pages. This option uses the least amount of resources but provides no protection against potentially serious problems. 
  
  Fonte: http://sqlserverpedia.com/wiki/Db_Config_-_PAGE_VERIFY_Option