[MySQL] Select Topic (9)

multiple choice

1. [Single-choice question] Common techniques for establishing redundant data for data recovery ( A ).
   A. Data dump and log file registration
   B. Data backup and encryption technology
   C. View and audit
   D. Database mirroring

2. [Single-choice question] If transaction T acquires an exclusive lock on data item Q, then T is on Q ( D ).
   A. Only read but not write
   B. Only write but not read
   C. Can not read and write
   D. Both read and write

3. [Single-choice question] What data inconsistencies will be brought about by concurrent operations? ( D )
   A. Lost modification, non-repeatable read, dirty read, deadlock
   B. Non-repeatable read, dirty read, deadlock
   C. Lost modification, dirty read, deadlock
   D. Lost modification, non-repeatable read, dirty read

4. 【Single-choice question】The important file used for database recovery is ( C ).
   A．database file
   B. index file
   C. log file
   D. Remarks file

5. [Single-choice question] If the system is running, due to some kind of hardware failure, part or all of the data stored in the external memory is lost, this situation is called (C ) .
   A．Business failure
   B. System failure
   C. Media failure
   D. malfunction

6. 【Single-choice question】If the system is running&#x